diff --git a/Realtime/Realtime/Conversation/LCIMConversationQuery.cs b/Realtime/Realtime/Conversation/LCIMConversationQuery.cs
index bc66d2e..372c1f8 100644
--- a/Realtime/Realtime/Conversation/LCIMConversationQuery.cs
+++ b/Realtime/Realtime/Conversation/LCIMConversationQuery.cs
@@ -52,6 +52,18 @@ namespace LeanCloud.Realtime {
             return this;
         }
 
+        /// <summary>
+        /// The value of key must not be contained in values.
+        /// </summary>
+        /// <param name="key"></param>
+        /// <param name="values"></param>
+        /// <returns></returns>
+        public LCIMConversationQuery WhereNotContainedIn(string key,
+            IEnumerable values) {
+            Condition.WhereNotContainedIn(key, values);
+            return this;
+        }
+
         /// <summary>
         /// The array corresponding to key contains all elements in values.
         /// </summary>