diff --git a/src/box_factory/builtin.rs b/src/box_factory/builtin.rs
new file mode 100644
index 00000000..ab74a1f1
--- /dev/null
+++ b/src/box_factory/builtin.rs
@@ -0,0 +1,307 @@
+/*!
+ * Builtin Box Factory
+ * 
+ * Handles creation of all built-in Box types (StringBox, IntegerBox, etc.)
+ * Replaces the 600+ line match statement with clean factory pattern
+ */
+
+use super::BoxFactory;
+use crate::box_trait::NyashBox;
+use crate::RuntimeError;
+use crate::boxes::*;
+use std::collections::HashMap;
+
+type BoxCreator = Box<dyn Fn(&[Box<dyn NyashBox>]) -> Result<Box<dyn NyashBox>, RuntimeError> + Send + Sync>;
+
+/// Factory for all built-in Box types
+pub struct BuiltinBoxFactory {
+    /// Map of Box type names to their creation functions
+    creators: HashMap<String, BoxCreator>,
+}
+
+impl BuiltinBoxFactory {
+    /// Create a new factory with all built-in types registered
+    pub fn new() -> Self {
+        let mut factory = Self {
+            creators: HashMap::new(),
+        };
+        
+        // Register all built-in Box types
+        factory.register_basic_types();
+        factory.register_container_types();
+        factory.register_utility_types();
+        factory.register_io_types();
+        #[cfg(not(target_arch = "wasm32"))]
+        factory.register_native_types();
+        #[cfg(target_arch = "wasm32")]
+        factory.register_wasm_types();
+        
+        factory
+    }
+    
+    /// Register basic data types
+    fn register_basic_types(&mut self) {
+        // StringBox
+        self.register("StringBox", |args| {
+            let value = match args.get(0) {
+                Some(arg) => arg.to_string_box().value,
+                None => String::new(),
+            };
+            Ok(Box::new(StringBox::new(value)))
+        });
+        
+        // IntegerBox
+        self.register("IntegerBox", |args| {
+            let value = match args.get(0) {
+                Some(arg) => {
+                    // Try direct downcast first
+                    if let Some(int_box) = arg.as_any().downcast_ref::<IntegerBox>() {
+                        int_box.value
+                    } else {
+                        // Parse from string
+                        arg.to_string_box().value.parse::<i64>()
+                            .map_err(|_| RuntimeError::TypeError {
+                                message: format!("Cannot convert '{}' to integer", arg.to_string_box().value),
+                            })?
+                    }
+                },
+                None => 0,
+            };
+            Ok(Box::new(IntegerBox::new(value)))
+        });
+        
+        // BoolBox
+        self.register("BoolBox", |args| {
+            let value = match args.get(0) {
+                Some(arg) => {
+                    if let Some(bool_box) = arg.as_any().downcast_ref::<BoolBox>() {
+                        bool_box.value
+                    } else {
+                        match arg.to_string_box().value.to_lowercase().as_str() {
+                            "true" => true,
+                            "false" => false,
+                            _ => return Err(RuntimeError::TypeError {
+                                message: format!("Cannot convert '{}' to boolean", arg.to_string_box().value),
+                            }),
+                        }
+                    }
+                },
+                None => false,
+            };
+            Ok(Box::new(BoolBox::new(value)))
+        });
+        
+        // FloatBox
+        self.register("FloatBox", |args| {
+            let value = match args.get(0) {
+                Some(arg) => {
+                    if let Some(float_box) = arg.as_any().downcast_ref::<FloatBox>() {
+                        float_box.value
+                    } else if let Some(int_box) = arg.as_any().downcast_ref::<IntegerBox>() {
+                        int_box.value as f64
+                    } else {
+                        arg.to_string_box().value.parse::<f64>()
+                            .map_err(|_| RuntimeError::TypeError {
+                                message: format!("Cannot convert '{}' to float", arg.to_string_box().value),
+                            })?
+                    }
+                },
+                None => 0.0,
+            };
+            Ok(Box::new(FloatBox::new(value)))
+        });
+        
+        // NullBox
+        self.register("NullBox", |_args| {
+            Ok(Box::new(NullBox::new()))
+        });
+    }
+    
+    /// Register container types
+    fn register_container_types(&mut self) {
+        // ArrayBox
+        self.register("ArrayBox", |args| {
+            if !args.is_empty() {
+                return Err(RuntimeError::InvalidOperation {
+                    message: format!("ArrayBox constructor expects 0 arguments, got {}", args.len()),
+                });
+            }
+            Ok(Box::new(ArrayBox::new()))
+        });
+        
+        // MapBox
+        self.register("MapBox", |args| {
+            if !args.is_empty() {
+                return Err(RuntimeError::InvalidOperation {
+                    message: format!("MapBox constructor expects 0 arguments, got {}", args.len()),
+                });
+            }
+            Ok(Box::new(MapBox::new()))
+        });
+        
+        // ResultBox
+        self.register("ResultBox", |args| {
+            if args.len() != 1 {
+                return Err(RuntimeError::InvalidOperation {
+                    message: format!("ResultBox constructor expects 1 argument, got {}", args.len()),
+                });
+            }
+            let value = args[0].clone_box();
+            Ok(Box::new(crate::boxes::result::NyashResultBox::new_ok(value)))
+        });
+    }
+    
+    /// Register utility types
+    fn register_utility_types(&mut self) {
+        // MathBox
+        self.register("MathBox", |args| {
+            if !args.is_empty() {
+                return Err(RuntimeError::InvalidOperation {
+                    message: format!("MathBox constructor expects 0 arguments, got {}", args.len()),
+                });
+            }
+            Ok(Box::new(MathBox::new()))
+        });
+        
+        // RandomBox
+        self.register("RandomBox", |args| {
+            if !args.is_empty() {
+                return Err(RuntimeError::InvalidOperation {
+                    message: format!("RandomBox constructor expects 0 arguments, got {}", args.len()),
+                });
+            }
+            Ok(Box::new(RandomBox::new()))
+        });
+        
+        // TimeBox
+        self.register("TimeBox", |args| {
+            if !args.is_empty() {
+                return Err(RuntimeError::InvalidOperation {
+                    message: format!("TimeBox constructor expects 0 arguments, got {}", args.len()),
+                });
+            }
+            Ok(Box::new(TimeBox::new()))
+        });
+        
+        // DebugBox
+        self.register("DebugBox", |args| {
+            if !args.is_empty() {
+                return Err(RuntimeError::InvalidOperation {
+                    message: format!("DebugBox constructor expects 0 arguments, got {}", args.len()),
+                });
+            }
+            Ok(Box::new(DebugBox::new()))
+        });
+    }
+    
+    /// Register I/O types
+    fn register_io_types(&mut self) {
+        // ConsoleBox
+        self.register("ConsoleBox", |args| {
+            if !args.is_empty() {
+                return Err(RuntimeError::InvalidOperation {
+                    message: format!("ConsoleBox constructor expects 0 arguments, got {}", args.len()),
+                });
+            }
+            Ok(Box::new(ConsoleBox::new()))
+        });
+        
+        // SoundBox
+        self.register("SoundBox", |args| {
+            if !args.is_empty() {
+                return Err(RuntimeError::InvalidOperation {
+                    message: format!("SoundBox constructor expects 0 arguments, got {}", args.len()),
+                });
+            }
+            Ok(Box::new(SoundBox::new()))
+        });
+    }
+    
+    /// Register native-only types
+    #[cfg(not(target_arch = "wasm32"))]
+    fn register_native_types(&mut self) {
+        // DateTimeBox
+        self.register("DateTimeBox", |args| {
+            if !args.is_empty() {
+                return Err(RuntimeError::InvalidOperation {
+                    message: format!("DateTimeBox constructor expects 0 arguments, got {}", args.len()),
+                });
+            }
+            Ok(Box::new(DateTimeBox::now()))
+        });
+        
+        // Additional native types can be registered here
+        #[cfg(all(feature = "gui", not(target_arch = "wasm32")))]
+        {
+            self.register("EguiBox", |args| {
+                if !args.is_empty() {
+                    return Err(RuntimeError::InvalidOperation {
+                        message: format!("EguiBox constructor expects 0 arguments, got {}", args.len()),
+                    });
+                }
+                Ok(Box::new(crate::boxes::EguiBox::new()))
+            });
+        }
+    }
+    
+    /// Register WASM-specific types
+    #[cfg(target_arch = "wasm32")]
+    fn register_wasm_types(&mut self) {
+        // WebDisplayBox
+        self.register("WebDisplayBox", |args| {
+            if args.len() != 1 {
+                return Err(RuntimeError::InvalidOperation {
+                    message: format!("WebDisplayBox constructor expects 1 argument (element_id), got {}", args.len()),
+                });
+            }
+            
+            if let Some(id_str) = args[0].as_any().downcast_ref::<StringBox>() {
+                Ok(Box::new(crate::boxes::WebDisplayBox::new(id_str.value.clone())))
+            } else {
+                Err(RuntimeError::TypeError {
+                    message: "WebDisplayBox constructor requires string element_id argument".to_string(),
+                })
+            }
+        });
+        
+        // Additional WASM types can be registered here
+    }
+    
+    /// Register a Box creator function
+    fn register<F>(&mut self, name: &str, creator: F)
+    where
+        F: Fn(&[Box<dyn NyashBox>]) -> Result<Box<dyn NyashBox>, RuntimeError> + Send + Sync + 'static,
+    {
+        self.creators.insert(name.to_string(), Box::new(creator));
+    }
+}
+
+impl BoxFactory for BuiltinBoxFactory {
+    fn create_box(
+        &self,
+        name: &str,
+        args: &[Box<dyn NyashBox>],
+    ) -> Result<Box<dyn NyashBox>, RuntimeError> {
+        if let Some(creator) = self.creators.get(name) {
+            creator(args)
+        } else {
+            Err(RuntimeError::InvalidOperation {
+                message: format!("Unknown built-in Box type: {}", name),
+            })
+        }
+    }
+    
+    fn box_types(&self) -> Vec<&str> {
+        self.creators.keys().map(|s| s.as_str()).collect()
+    }
+}
+
+/// Declarative macro for registering multiple Box types at once
+#[macro_export]
+macro_rules! register_builtins {
+    ($factory:expr, $($box_name:literal => $creator_fn:expr),* $(,)?) => {
+        $(
+            $factory.register($box_name, $creator_fn);
+        )*
+    };
+}
\ No newline at end of file
diff --git a/src/box_factory/mod.rs b/src/box_factory/mod.rs
new file mode 100644
index 00000000..03ecbf4c
--- /dev/null
+++ b/src/box_factory/mod.rs
@@ -0,0 +1,135 @@
+/*!
+ * Unified Box Factory Architecture
+ * 
+ * Phase 9.78: 統合BoxFactoryアーキテクチャ
+ * すべてのBox生成（ビルトイン、ユーザー定義、プラグイン）を統一的に扱う
+ * 
+ * Design principles:
+ * - "Everything is Box" 哲学の実装レベルでの体現
+ * - birth/finiライフサイクルの明確な責務分離
+ * - 保守性と拡張性の劇的向上
+ */
+
+use crate::box_trait::NyashBox;
+use crate::RuntimeError;
+use std::collections::HashMap;
+use std::sync::{Arc, RwLock};
+
+/// Unified interface for all Box creation
+pub trait BoxFactory: Send + Sync {
+    /// Create a new Box instance with given arguments
+    fn create_box(
+        &self,
+        name: &str,
+        args: &[Box<dyn NyashBox>],
+    ) -> Result<Box<dyn NyashBox>, RuntimeError>;
+    
+    /// Check if this factory is currently available
+    fn is_available(&self) -> bool {
+        true
+    }
+    
+    /// Get list of Box types this factory can create
+    fn box_types(&self) -> Vec<&str>;
+    
+    /// Check if this factory supports birth/fini lifecycle
+    fn supports_birth(&self) -> bool {
+        true
+    }
+}
+
+/// Registry that manages all BoxFactory implementations
+pub struct UnifiedBoxRegistry {
+    /// Ordered list of factories (priority: builtin > user > plugin)
+    pub factories: Vec<Arc<dyn BoxFactory>>,
+    
+    /// Quick lookup cache for performance
+    type_cache: RwLock<HashMap<String, usize>>, // maps type name to factory index
+}
+
+impl UnifiedBoxRegistry {
+    /// Create a new empty registry
+    pub fn new() -> Self {
+        Self {
+            factories: Vec::new(),
+            type_cache: RwLock::new(HashMap::new()),
+        }
+    }
+    
+    /// Register a new factory
+    pub fn register(&mut self, factory: Arc<dyn BoxFactory>) {
+        // Get all types this factory can create
+        let types = factory.box_types();
+        let factory_index = self.factories.len();
+        
+        // Update cache
+        let mut cache = self.type_cache.write().unwrap();
+        for type_name in types {
+            // First registered factory wins (priority order)
+            cache.entry(type_name.to_string())
+                .or_insert(factory_index);
+        }
+        
+        self.factories.push(factory);
+    }
+    
+    /// Create a Box using the unified interface
+    pub fn create_box(
+        &self,
+        name: &str,
+        args: &[Box<dyn NyashBox>],
+    ) -> Result<Box<dyn NyashBox>, RuntimeError> {
+        // Check cache first
+        let cache = self.type_cache.read().unwrap();
+        if let Some(&factory_index) = cache.get(name) {
+            if let Some(factory) = self.factories.get(factory_index) {
+                if factory.is_available() {
+                    return factory.create_box(name, args);
+                }
+            }
+        }
+        drop(cache);
+        
+        // Fallback: linear search through all factories
+        for factory in &self.factories {
+            if factory.box_types().contains(&name) && factory.is_available() {
+                return factory.create_box(name, args);
+            }
+        }
+        
+        Err(RuntimeError::InvalidOperation {
+            message: format!("Unknown Box type: {}", name),
+        })
+    }
+    
+    /// Get all available Box types
+    pub fn available_types(&self) -> Vec<String> {
+        let mut types = Vec::new();
+        for factory in &self.factories {
+            if factory.is_available() {
+                for type_name in factory.box_types() {
+                    types.push(type_name.to_string());
+                }
+            }
+        }
+        types.sort();
+        types.dedup();
+        types
+    }
+}
+
+/// Re-export submodules
+pub mod builtin;
+pub mod user_defined;
+pub mod plugin;
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    
+    #[test]
+    fn test_registry_creation() {
+        let registry = UnifiedBoxRegistry::new();
+        assert_eq!(registry.available_types().len(), 0);
+    }
+}
\ No newline at end of file
diff --git a/src/box_factory/plugin.rs b/src/box_factory/plugin.rs
new file mode 100644
index 00000000..b8b6cde1
--- /dev/null
+++ b/src/box_factory/plugin.rs
@@ -0,0 +1,57 @@
+/*!
+ * Plugin Box Factory
+ * 
+ * Handles creation of plugin-based Box types through BID/FFI system
+ * Integrates with v2 plugin system (BoxFactoryRegistry)
+ */
+
+use super::BoxFactory;
+use crate::box_trait::NyashBox;
+use crate::RuntimeError;
+use crate::runtime::get_global_registry;
+
+/// Factory for plugin-based Box types
+pub struct PluginBoxFactory {
+    // Uses the global BoxFactoryRegistry from v2 plugin system
+}
+
+impl PluginBoxFactory {
+    pub fn new() -> Self {
+        Self {}
+    }
+}
+
+impl BoxFactory for PluginBoxFactory {
+    fn create_box(
+        &self,
+        name: &str,
+        args: &[Box<dyn NyashBox>],
+    ) -> Result<Box<dyn NyashBox>, RuntimeError> {
+        // Use the existing v2 plugin system
+        let registry = get_global_registry();
+        
+        if let Some(_provider) = registry.get_provider(name) {
+            registry.create_box(name, args)
+                .map_err(|e| RuntimeError::InvalidOperation {
+                    message: format!("Plugin Box creation failed: {}", e),
+                })
+        } else {
+            Err(RuntimeError::InvalidOperation {
+                message: format!("No plugin provider for Box type: {}", name),
+            })
+        }
+    }
+    
+    fn box_types(&self) -> Vec<&str> {
+        // TODO: Get list from BoxFactoryRegistry
+        // For now, return empty as registry doesn't expose this yet
+        vec![]
+    }
+    
+    fn is_available(&self) -> bool {
+        // Check if any plugins are loaded
+        let registry = get_global_registry();
+        // TODO: Add method to check if registry has any providers
+        true
+    }
+}
\ No newline at end of file
diff --git a/src/box_factory/user_defined.rs b/src/box_factory/user_defined.rs
new file mode 100644
index 00000000..7a083615
--- /dev/null
+++ b/src/box_factory/user_defined.rs
@@ -0,0 +1,54 @@
+/*!
+ * User-Defined Box Factory
+ * 
+ * Handles creation of user-defined Box types through InstanceBox
+ * Manages inheritance, fields, methods, and birth/fini lifecycle
+ */
+
+use super::BoxFactory;
+use crate::box_trait::NyashBox;
+use crate::RuntimeError;
+
+/// Factory for user-defined Box types
+pub struct UserDefinedBoxFactory {
+    // TODO: This will need access to the interpreter context
+    // to look up box declarations and execute constructors
+    // For now, this is a placeholder
+}
+
+impl UserDefinedBoxFactory {
+    pub fn new() -> Self {
+        Self {
+            // TODO: Initialize with interpreter reference
+        }
+    }
+}
+
+impl BoxFactory for UserDefinedBoxFactory {
+    fn create_box(
+        &self,
+        _name: &str,
+        _args: &[Box<dyn NyashBox>],
+    ) -> Result<Box<dyn NyashBox>, RuntimeError> {
+        // TODO: Implementation will be moved from objects.rs
+        // This will:
+        // 1. Look up box declaration
+        // 2. Create InstanceBox with fields and methods
+        // 3. Execute birth constructor if present
+        // 4. Return the instance
+        
+        Err(RuntimeError::InvalidOperation {
+            message: "User-defined Box factory not yet implemented".to_string(),
+        })
+    }
+    
+    fn box_types(&self) -> Vec<&str> {
+        // TODO: Return list of registered user-defined Box types
+        vec![]
+    }
+    
+    fn is_available(&self) -> bool {
+        // TODO: Check if interpreter context is available
+        false
+    }
+}
\ No newline at end of file
diff --git a/src/lib.rs b/src/lib.rs
index da29e7df..b48b1fdf 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -10,6 +10,7 @@ use wasm_bindgen::prelude::*;
 
 pub mod box_trait;
 pub mod boxes;
+pub mod box_factory; // 🏭 Unified Box Factory Architecture (Phase 9.78)
 pub mod stdlib;
 pub mod environment;
 pub mod tokenizer;
diff --git a/src/runtime/mod.rs b/src/runtime/mod.rs
index 2da3335a..8a422731 100644
--- a/src/runtime/mod.rs
+++ b/src/runtime/mod.rs
@@ -5,6 +5,7 @@
 pub mod plugin_config;
 pub mod box_registry;
 pub mod plugin_loader_v2;
+pub mod unified_registry;
 // pub mod plugin_box;  // legacy - 古いPluginBox
 // pub mod plugin_loader;  // legacy - Host VTable使用
 
@@ -14,6 +15,7 @@ mod tests;
 pub use plugin_config::PluginConfig;
 pub use box_registry::{BoxFactoryRegistry, BoxProvider, get_global_registry};
 pub use plugin_loader_v2::{PluginLoaderV2, get_global_loader_v2, init_global_loader_v2};
+pub use unified_registry::{get_global_unified_registry, init_global_unified_registry, register_user_defined_factory};
 // pub use plugin_box::PluginBox;  // legacy
 // Use unified plugin loader (formerly v2)
 // pub use plugin_loader::{PluginLoaderV2 as PluginLoader, get_global_loader_v2 as get_global_loader};  // legacy
\ No newline at end of file
diff --git a/src/runtime/unified_registry.rs b/src/runtime/unified_registry.rs
new file mode 100644
index 00000000..e44e5403
--- /dev/null
+++ b/src/runtime/unified_registry.rs
@@ -0,0 +1,49 @@
+/*!
+ * Global Unified Box Registry
+ * 
+ * Manages the global instance of UnifiedBoxRegistry
+ * Integrates all Box creation sources (builtin, user-defined, plugin)
+ */
+
+use crate::box_factory::{UnifiedBoxRegistry, builtin::BuiltinBoxFactory, plugin::PluginBoxFactory};
+use std::sync::{Arc, Mutex, OnceLock};
+
+/// Global registry instance
+static GLOBAL_REGISTRY: OnceLock<Arc<Mutex<UnifiedBoxRegistry>>> = OnceLock::new();
+
+/// Initialize the global unified registry
+pub fn init_global_unified_registry() {
+    GLOBAL_REGISTRY.get_or_init(|| {
+        let mut registry = UnifiedBoxRegistry::new();
+        
+        // Register built-in Box factory (highest priority)
+        registry.register(Arc::new(BuiltinBoxFactory::new()));
+        
+        // Register plugin Box factory (lowest priority)
+        registry.register(Arc::new(PluginBoxFactory::new()));
+        
+        // TODO: User-defined Box factory will be registered by interpreter
+        
+        Arc::new(Mutex::new(registry))
+    });
+}
+
+/// Get the global unified registry
+pub fn get_global_unified_registry() -> Arc<Mutex<UnifiedBoxRegistry>> {
+    init_global_unified_registry();
+    GLOBAL_REGISTRY.get().unwrap().clone()
+}
+
+/// Register a user-defined Box factory (called by interpreter)
+pub fn register_user_defined_factory(factory: Arc<dyn crate::box_factory::BoxFactory>) {
+    let registry = get_global_unified_registry();
+    let mut registry_lock = registry.lock().unwrap();
+    
+    // Insert at position 1 (after builtin, before plugin)
+    // This maintains priority: builtin > user > plugin
+    if registry_lock.factories.len() >= 2 {
+        registry_lock.factories.insert(1, factory);
+    } else {
+        registry_lock.register(factory);
+    }
+}
\ No newline at end of file