diff --git a/nanobot/channels/dingtalk.py b/nanobot/channels/dingtalk.py
index 8e2a2be..bd6a8c2 100644
--- a/nanobot/channels/dingtalk.py
+++ b/nanobot/channels/dingtalk.py
@@ -315,7 +315,7 @@ class DingTalkChannel(BaseChannel):
             payload = {
                 "robotCode": self.config.client_id,
                 "openConversationId": chat_id[6:],  # Remove "group:" prefix,
-                "msgKey": "sampleMarkdown",
+                "msgKey": "msg_key",
                 "msgParam": json.dumps(msg_param, ensure_ascii=False),
             }
         else: