diff --git a/tutorial/autofinetune-nlp.md b/tutorial/autofinetune-nlp.md
index 5366798f02e8c7e029916ed058b8748d1094e75e..c3ccc7b22e8fcfe0e8628008dca4e16509e9dd9a 100644
--- a/tutorial/autofinetune-nlp.md
+++ b/tutorial/autofinetune-nlp.md
@@ -133,8 +133,9 @@ if __name__ == '__main__':
     eval_avg_score, eval_avg_loss, eval_run_speed = cls_task._calculate_metrics(run_states)
 
     # Move ckpt/best_model to the defined saved parameters directory
-    if is_path_valid(args.saved_params_dir) and os.path.exists(config.checkpoint_dir+"/best_model/"):
-        shutil.copytree(config.checkpoint_dir+"/best_model/", args.saved_params_dir)
+    best_model_dir = os.path.join(config.checkpoint_dir, "best_model")
+    if is_path_valid(args.saved_params_dir) and os.path.exists(best_model_dir):
+        shutil.copytree(best_model_dir, args.saved_params_dir)
         shutil.rmtree(config.checkpoint_dir)
 
     print("AutoFinetuneEval"+"\t"+str(float(eval_avg_score["acc"])))