diff --git a/paddlespeech/s2t/decoders/recog.py b/paddlespeech/s2t/decoders/recog.py
index 88955eacb16..2d2aa210919 100644
--- a/paddlespeech/s2t/decoders/recog.py
+++ b/paddlespeech/s2t/decoders/recog.py
@@ -12,6 +12,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 # Reference espnet Apache 2.0 (http://www.apache.org/licenses/LICENSE-2.0)
+# Modified from espnet(https://github.com/espnet/espnet)
 """V2 backend for `asr_recog.py` using py:class:`decoders.beam_search.BeamSearch`."""
 import jsonlines
 import paddle
diff --git a/paddlespeech/s2t/decoders/recog_bin.py b/paddlespeech/s2t/decoders/recog_bin.py
index 0470a0344df..37b49f3a059 100644
--- a/paddlespeech/s2t/decoders/recog_bin.py
+++ b/paddlespeech/s2t/decoders/recog_bin.py
@@ -12,6 +12,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 # Reference espnet Apache 2.0 (http://www.apache.org/licenses/LICENSE-2.0)
+# Modified from espnet(https://github.com/espnet/espnet)
 """End-to-end speech recognition model decoding script."""
 import logging
 import os
diff --git a/paddlespeech/s2t/models/u2/u2.py b/paddlespeech/s2t/models/u2/u2.py
index 51388586f97..6a98607b697 100644
--- a/paddlespeech/s2t/models/u2/u2.py
+++ b/paddlespeech/s2t/models/u2/u2.py
@@ -11,6 +11,7 @@
 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 # See the License for the specific language governing permissions and
 # limitations under the License.
+# Modified from wenet(https://github.com/wenet-e2e/wenet)
 """U2 ASR Model
 Unified Streaming and Non-streaming Two-pass End-to-end Model for Speech Recognition
 (https://arxiv.org/pdf/2012.05481.pdf)
diff --git a/paddlespeech/s2t/models/u2/updater.py b/paddlespeech/s2t/models/u2/updater.py
index bb18fe4160d..c59090a84ee 100644
--- a/paddlespeech/s2t/models/u2/updater.py
+++ b/paddlespeech/s2t/models/u2/updater.py
@@ -11,6 +11,7 @@
 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 # See the License for the specific language governing permissions and
 # limitations under the License.
+# Modified from wenet(https://github.com/wenet-e2e/wenet)
 from contextlib import nullcontext
 
 import paddle
diff --git a/paddlespeech/s2t/models/u2_st/u2_st.py b/paddlespeech/s2t/models/u2_st/u2_st.py
index 999723e5100..6447753c50f 100644
--- a/paddlespeech/s2t/models/u2_st/u2_st.py
+++ b/paddlespeech/s2t/models/u2_st/u2_st.py
@@ -11,6 +11,7 @@
 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 # See the License for the specific language governing permissions and
 # limitations under the License.
+# Modified from wenet(https://github.com/wenet-e2e/wenet)
 """U2 ASR Model
 Unified Streaming and Non-streaming Two-pass End-to-end Model for Speech Recognition
 (https://arxiv.org/pdf/2012.05481.pdf)
diff --git a/paddlespeech/s2t/utils/bleu_score.py b/paddlespeech/s2t/utils/bleu_score.py
index a50c000ae91..d7eb9c7c687 100644
--- a/paddlespeech/s2t/utils/bleu_score.py
+++ b/paddlespeech/s2t/utils/bleu_score.py
@@ -11,6 +11,7 @@
 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 # See the License for the specific language governing permissions and
 # limitations under the License.
+# Modified from espnet(https://github.com/espnet/espnet)
 """This module provides functions to calculate bleu score in different level.
 e.g. wer for word-level, cer for char-level.
 """
diff --git a/paddlespeech/s2t/utils/text_grid.py b/paddlespeech/s2t/utils/text_grid.py
index 3af58c9ba60..cbd9856e40d 100644
--- a/paddlespeech/s2t/utils/text_grid.py
+++ b/paddlespeech/s2t/utils/text_grid.py
@@ -11,6 +11,7 @@
 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 # See the License for the specific language governing permissions and
 # limitations under the License.
+# Modified from wenet(https://github.com/wenet-e2e/wenet)
 from typing import Dict
 from typing import List
 from typing import Text