diff --git a/metagpt/memory/memory.py b/metagpt/memory/memory.py
index 5dbadf9c38..4a00d8332f 100644
--- a/metagpt/memory/memory.py
+++ b/metagpt/memory/memory.py
@@ -24,6 +24,17 @@ class Memory(BaseModel):
     index: DefaultDict[str, list[SerializeAsAny[Message]]] = Field(default_factory=lambda: defaultdict(list))
     ignore_id: bool = False
 
+    def _filter_expired_messages(self, messages: list[Message]) -> list[Message]:
+        """Filter out expired messages from the given list.
+        
+        Args:
+            messages: List of messages to filter.
+            
+        Returns:
+            List of non-expired messages.
+        """
+        return [message for message in messages if not message.is_expired()]
+
     def add(self, message: Message):
         """Add a new message to storage, while updating the index"""
         if self.ignore_id:
@@ -40,11 +51,13 @@ def add_batch(self, messages: Iterable[Message]):
 
     def get_by_role(self, role: str) -> list[Message]:
         """Return all messages of a specified role"""
-        return [message for message in self.storage if message.role == role]
+        messages = [message for message in self.storage if message.role == role]
+        return self._filter_expired_messages(messages)
 
     def get_by_content(self, content: str) -> list[Message]:
         """Return all messages containing a specified content"""
-        return [message for message in self.storage if content in message.content]
+        messages = [message for message in self.storage if content in message.content]
+        return self._filter_expired_messages(messages)
 
     def delete_newest(self) -> "Message":
         """delete the newest message from the storage"""
@@ -75,11 +88,13 @@ def count(self) -> int:
 
     def try_remember(self, keyword: str) -> list[Message]:
         """Try to recall all messages containing a specified keyword"""
-        return [message for message in self.storage if keyword in message.content]
+        messages = [message for message in self.storage if keyword in message.content]
+        return self._filter_expired_messages(messages)
 
     def get(self, k=0) -> list[Message]:
         """Return the most recent k memories, return all when k=0"""
-        return self.storage[-k:]
+        messages = self.storage[-k:]
+        return self._filter_expired_messages(messages)
 
     def find_news(self, observed: list[Message], k=0) -> list[Message]:
         """find news (previously unseen messages) from the most recent k memories, from all memories when k=0"""
@@ -94,7 +109,8 @@ def find_news(self, observed: list[Message], k=0) -> list[Message]:
     def get_by_action(self, action) -> list[Message]:
         """Return all messages triggered by a specified Action"""
         index = any_to_str(action)
-        return self.index[index]
+        messages = self.index[index]
+        return self._filter_expired_messages(messages)
 
     def get_by_actions(self, actions: Set) -> list[Message]:
         """Return all messages triggered by specified Actions"""
@@ -104,9 +120,12 @@ def get_by_actions(self, actions: Set) -> list[Message]:
             if action not in self.index:
                 continue
             rsp += self.index[action]
-        return rsp
+        return self._filter_expired_messages(rsp)
 
     @handle_exception
     def get_by_position(self, position: int) -> Optional[Message]:
-        """Returns the message at the given position if valid, otherwise returns None"""
-        return self.storage[position]
+        """Returns the message at the given position if valid and not expired, otherwise returns None"""
+        message = self.storage[position]
+        if message and message.is_expired():
+            return None
+        return message
diff --git a/metagpt/schema.py b/metagpt/schema.py
index 52badcc21a..a82143c16b 100644
--- a/metagpt/schema.py
+++ b/metagpt/schema.py
@@ -240,6 +240,8 @@ class Message(BaseModel):
     sent_from: str = Field(default="", validate_default=True)
     send_to: set[str] = Field(default={MESSAGE_ROUTE_TO_ALL}, validate_default=True)
     metadata: Dict[str, Any] = Field(default_factory=dict)  # metadata for `content` and `instruct_content`
+    ttl: int = Field(default=-1, validate_default=True)  # Time-To-Live in seconds, -1 means never expire
+    created_at: float = Field(default_factory=time.time)  # Creation time in seconds since epoch
 
     @field_validator("id", mode="before")
     @classmethod
@@ -415,6 +417,18 @@ def is_user_message(self) -> bool:
     def is_ai_message(self) -> bool:
         return self.role == "assistant"
 
+    def is_expired(self) -> bool:
+        """Check if the message has expired based on its TTL.
+        
+        Returns:
+            bool: True if the message has expired, False otherwise.
+                  Messages with ttl=-1 never expire.
+        """
+        if self.ttl == -1:
+            return False
+        current_time = time.time()
+        return current_time - self.created_at > self.ttl
+
 
 class UserMessage(Message):
     """便于支持OpenAI的消息
diff --git a/tests/metagpt/memory/test_memory.py b/tests/metagpt/memory/test_memory.py
index a072b61deb..8b066bb71a 100644
--- a/tests/metagpt/memory/test_memory.py
+++ b/tests/metagpt/memory/test_memory.py
@@ -2,6 +2,8 @@
 # -*- coding: utf-8 -*-
 # @Desc   : the unittest of Memory
 
+import time
+
 from metagpt.actions import UserRequirement
 from metagpt.memory.memory import Memory
 from metagpt.schema import Message
@@ -55,3 +57,135 @@ def test_memory():
     memory.clear()
     assert memory.count() == 0
     assert len(memory.index) == 0
+
+
+def test_message_ttl_and_created_at():
+    """Test Message class ttl and created_at fields"""
+    # Test default values
+    message = Message(content="test message", role="user")
+    assert message.ttl == -1
+    assert message.created_at > 0
+    
+    # Test custom ttl
+    message_with_ttl = Message(content="test message with ttl", role="user", ttl=60)
+    assert message_with_ttl.ttl == 60
+    
+    # Test is_expired method for ttl=-1 (never expire)
+    assert message.is_expired() == False
+    
+    # Test serialization
+    dumped = message.dump()
+    loaded = Message.load(dumped)
+    assert loaded.ttl == message.ttl
+    assert abs(loaded.created_at - message.created_at) < 0.001
+
+
+def test_message_expiration():
+    """Test message expiration functionality"""
+    # Create a message that expires in 1 second
+    message = Message(content="expiring message", role="user", ttl=1)
+    assert message.is_expired() == False
+    
+    # Wait for message to expire
+    time.sleep(1.1)
+    assert message.is_expired() == True
+    
+    # Create a message that never expires
+    message_never_expire = Message(content="never expiring message", role="user", ttl=-1)
+    assert message_never_expire.is_expired() == False
+    
+    # Wait and verify it still doesn't expire
+    time.sleep(0.5)
+    assert message_never_expire.is_expired() == False
+
+
+def test_memory_filter_expired_messages():
+    """Test Memory class filtering expired messages"""
+    memory = Memory()
+    
+    # Create messages with different TTLs
+    message1 = Message(content="never expire", role="user1", ttl=-1)
+    message2 = Message(content="expire in 1 sec", role="user2", ttl=1)
+    message3 = Message(content="never expire too", role="user1", ttl=-1)
+    
+    # Add all messages to memory
+    memory.add_batch([message1, message2, message3])
+    assert memory.count() == 3
+    
+    # Wait for message2 to expire
+    time.sleep(1.1)
+    
+    # Test get() method filters expired messages
+    messages = memory.get()
+    assert len(messages) == 2
+    assert message2 not in messages
+    
+    # Test get_by_role() method filters expired messages
+    messages = memory.get_by_role("user2")
+    assert len(messages) == 0
+    
+    # Test get_by_role() for non-expired messages
+    messages = memory.get_by_role("user1")
+    assert len(messages) == 2
+    
+    # Test get_by_content() method filters expired messages
+    messages = memory.get_by_content("expire")
+    assert len(messages) == 2
+    assert message2 not in messages
+    
+    # Test try_remember() method filters expired messages
+    messages = memory.try_remember("expire")
+    assert len(messages) == 2
+    assert message2 not in messages
+    
+    # Test get_by_action() method filters expired messages
+    messages = memory.get_by_action(UserRequirement)
+    assert len(messages) == 2
+    assert message2 not in messages
+    
+    # Test get_by_actions() method filters expired messages
+    messages = memory.get_by_actions({UserRequirement})
+    assert len(messages) == 2
+    assert message2 not in messages
+    
+    # Test get_by_position() method returns None for expired messages
+    # Note: message2 is at position 1 in storage
+    message = memory.get_by_position(1)
+    assert message is None
+
+
+def test_memory_backward_compatibility():
+    """Test backward compatibility with existing code"""
+    memory = Memory()
+    
+    # Create messages without specifying ttl (should use default -1)
+    message1 = Message(content="message1", role="user1")
+    message2 = Message(content="message2", role="user2")
+    
+    # Verify default ttl is -1
+    assert message1.ttl == -1
+    assert message2.ttl == -1
+    
+    # Add to memory
+    memory.add_batch([message1, message2])
+    
+    # Verify all retrieval methods work as before
+    assert memory.count() == 2
+    
+    messages = memory.get()
+    assert len(messages) == 2
+    
+    messages = memory.get_by_role("user1")
+    assert len(messages) == 1
+    assert messages[0].content == "message1"
+    
+    messages = memory.get_by_content("message")
+    assert len(messages) == 2
+    
+    # Verify messages don't expire
+    time.sleep(0.5)
+    assert message1.is_expired() == False
+    assert message2.is_expired() == False
+    
+    messages = memory.get()
+    assert len(messages) == 2