diff --git a/src/llmtuner/api/chat.py b/src/llmtuner/api/chat.py
index fa2f0d03..972ee906 100644
--- a/src/llmtuner/api/chat.py
+++ b/src/llmtuner/api/chat.py
@@ -103,6 +103,7 @@ async def create_chat_completion_response(
         top_p=request.top_p,
         max_new_tokens=request.max_tokens,
         num_return_sequences=request.n,
+        stop=request.stop
     )
 
     prompt_length, response_length = 0, 0
@@ -155,6 +156,7 @@ async def create_stream_chat_completion_response(
         temperature=request.temperature,
         top_p=request.top_p,
         max_new_tokens=request.max_tokens,
+        stop=request.stop
     ):
         if len(new_token) != 0:
             yield _create_stream_chat_completion_chunk(
diff --git a/src/llmtuner/api/protocol.py b/src/llmtuner/api/protocol.py
index ae6e2e9b..f526c813 100644
--- a/src/llmtuner/api/protocol.py
+++ b/src/llmtuner/api/protocol.py
@@ -1,6 +1,6 @@
 import time
 from enum import Enum, unique
-from typing import Any, Dict, List, Optional
+from typing import Any, Dict, List, Optional, Union
 
 from pydantic import BaseModel, Field
 from typing_extensions import Literal
@@ -78,6 +78,7 @@ class ChatCompletionRequest(BaseModel):
     n: int = 1
     max_tokens: Optional[int] = None
     stream: bool = False
+    stop: Union[Optional[str], List[str]] = None
 
 
 class ChatCompletionResponseChoice(BaseModel):
diff --git a/src/llmtuner/chat/vllm_engine.py b/src/llmtuner/chat/vllm_engine.py
index 0f0dc366..d50e41aa 100644
--- a/src/llmtuner/chat/vllm_engine.py
+++ b/src/llmtuner/chat/vllm_engine.py
@@ -96,6 +96,7 @@ class VllmEngine(BaseEngine):
         repetition_penalty = input_kwargs.pop("repetition_penalty", None)
         max_length = input_kwargs.pop("max_length", None)
         max_new_tokens = input_kwargs.pop("max_new_tokens", None)
+        stop = input_kwargs.pop("stop", None)
 
         generating_args = self.generating_args.copy()
         generating_args.update(
@@ -122,6 +123,7 @@ class VllmEngine(BaseEngine):
             top_k=generating_args["top_k"],
             use_beam_search=generating_args["num_beams"] > 1,
             length_penalty=generating_args["length_penalty"],
+            stop=stop,
             stop_token_ids=[self.tokenizer.eos_token_id] + self.tokenizer.additional_special_tokens_ids,
             max_tokens=generating_args["max_new_tokens"],
             skip_special_tokens=True,