diff --git a/src/boxes/socket_box.rs b/src/boxes/socket_box.rs
index 65f5b25b..12a57acd 100644
--- a/src/boxes/socket_box.rs
+++ b/src/boxes/socket_box.rs
@@ -56,12 +56,18 @@ pub struct SocketBox {
 
 impl Clone for SocketBox {
     fn clone(&self) -> Self {
+        // Read the current state values atomically
+        let current_is_server = *self.is_server.lock().unwrap();
+        let current_is_connected = *self.is_connected.lock().unwrap();
+        
+        // For listener and stream, we can't clone them, so we'll share them
+        // but create new Arc instances with the current state
         Self {
             base: BoxBase::new(), // New unique ID for clone
-            listener: Arc::clone(&self.listener),
-            stream: Arc::clone(&self.stream),
-            is_server: Arc::clone(&self.is_server),
-            is_connected: Arc::clone(&self.is_connected),
+            listener: Arc::clone(&self.listener),  // Share the same listener
+            stream: Arc::clone(&self.stream),      // Share the same stream  
+            is_server: Arc::new(Mutex::new(current_is_server)),     // New Arc with current value
+            is_connected: Arc::new(Mutex::new(current_is_connected)), // New Arc with current value
         }
     }
 }
@@ -314,7 +320,8 @@ impl SocketBox {
     
     /// サーバーモード確認
     pub fn is_server(&self) -> Box<dyn NyashBox> {
-        Box::new(BoolBox::new(*self.is_server.lock().unwrap()))
+        let is_server_value = *self.is_server.lock().unwrap();
+        Box::new(BoolBox::new(is_server_value))
     }
 }
 
diff --git a/src/interpreter/expressions.rs b/src/interpreter/expressions.rs
index 310d9aa9..d004299a 100644
--- a/src/interpreter/expressions.rs
+++ b/src/interpreter/expressions.rs
@@ -455,7 +455,22 @@ impl NyashInterpreter {
         
         // SocketBox method calls
         if let Some(socket_box) = obj_value.as_any().downcast_ref::<SocketBox>() {
-            return self.execute_socket_method(socket_box, method, arguments);
+            let result = self.execute_socket_method(socket_box, method, arguments)?;
+            
+            // 🔧 FIX: Update stored variable for stateful SocketBox methods
+            // These methods modify the SocketBox internal state, so we need to update
+            // the stored local variable to ensure subsequent accesses get the updated state
+            if matches!(method, "bind" | "connect" | "close") {
+                if let ASTNode::Variable { name, .. } = object {
+                    if let Some(stored_var) = self.local_vars.get_mut(name) {
+                        // Replace the stored instance with the modified one
+                        let updated_instance = socket_box.clone();
+                        *stored_var = Box::new(updated_instance);
+                    }
+                }
+            }
+            
+            return Ok(result);
         }
         
         // HTTPServerBox method calls
diff --git a/test_arc_sharing.nyash b/test_arc_sharing.nyash
new file mode 100644
index 00000000..312c84af
--- /dev/null
+++ b/test_arc_sharing.nyash
@@ -0,0 +1,24 @@
+// Test Arc sharing issue
+static box Main {
+    main() {
+        print("🔬 Testing Arc sharing...")
+        
+        local socket1
+        socket1 = new SocketBox()
+        
+        local socket2  
+        socket2 = socket1  // This should clone
+        
+        print("Before bind - socket1.isServer(): " + socket1.isServer().toString())
+        print("Before bind - socket2.isServer(): " + socket2.isServer().toString())
+        
+        socket1.bind("127.0.0.1", 8080)
+        
+        print("After bind - socket1.isServer(): " + socket1.isServer().toString())
+        print("After bind - socket2.isServer(): " + socket2.isServer().toString())
+        
+        socket1.close()
+        
+        return true
+    }
+}
\ No newline at end of file
diff --git a/test_socket_simple.nyash b/test_socket_simple.nyash
new file mode 100644
index 00000000..9733199c
--- /dev/null
+++ b/test_socket_simple.nyash
@@ -0,0 +1,23 @@
+// Simple test for SocketBox state sharing
+static box Main {
+    main() {
+        print("🧪 Testing SocketBox state sharing...")
+        
+        local socket
+        socket = new SocketBox()
+        
+        print("Initial isServer: " + socket.isServer().toString())
+        
+        local bindOk
+        bindOk = socket.bind("127.0.0.1", 8080)
+        print("Bind result: " + bindOk.toString())
+        
+        print("After bind isServer: " + socket.isServer().toString())
+        
+        local closeOk
+        closeOk = socket.close()
+        print("Close result: " + closeOk.toString())
+        
+        return true
+    }
+}
\ No newline at end of file