diff --git a/generate.py b/generate.py
index 4f114d4..284ae6a 100644
--- a/generate.py
+++ b/generate.py
@@ -58,17 +58,24 @@ def _validate_args(args):
     assert args.task in WAN_CONFIGS, f"Unsupport task: {args.task}"
     assert args.task in EXAMPLE_PROMPT, f"Unsupport task: {args.task}"
 
-    # TODO(wangang.wa): need to be confirmed
     # The default sampling steps are 40 for image-to-video tasks and 50 for text-to-video tasks.
     if args.sample_steps is None:
-        args.sample_steps = 40 if "i2v" in args.task else 50
+        args.sample_steps = 50
+        if "vace" in args.task:
+            args.sample_steps = 25
+        elif "i2v" in args.task:
+            args.sample_steps = 40
+
 
     if args.sample_shift is None:
         args.sample_shift = 5.0
         if "i2v" in args.task and args.size in ["832*480", "480*832"]:
             args.sample_shift = 3.0
-        if "flf2v" in args.task:
+        elif "flf2v" in args.task:
             args.sample_shift = 16
+        elif "vace" in args.task:
+            args.sample_shift = 3.0
+
 
     # The default number of frames are 1 for text-to-image tasks and 81 for other tasks.
     if args.frame_num is None: