diff --git a/funasr/utils/timestamp_tools.py b/funasr/utils/timestamp_tools.py
index 6abebe165..4fc2d15c5 100644
--- a/funasr/utils/timestamp_tools.py
+++ b/funasr/utils/timestamp_tools.py
@@ -156,6 +156,7 @@ def timestamp_sentence(
 
         punc_id = int(punc_id) if punc_id is not None else 1
         sentence_end = timestamp[1] if timestamp is not None else sentence_end
+        sentence_start = timestamp[0] if timestamp is not None else sentence_start
         sentence_text_seg = (
             sentence_text_seg[:-1] if sentence_text_seg[-1] == " " else sentence_text_seg
         )
@@ -183,7 +184,6 @@ def timestamp_sentence(
             sentence_text = ""
             sentence_text_seg = ""
             ts_list = []
-            sentence_start = sentence_end
     return res