diff --git a/egs/aishell/ASR/conformer_ctc/generate_CTC_label.py b/egs/aishell/ASR/conformer_ctc/generate_CTC_label.py
index 49818f1fc..4868be2d2 100755
--- a/egs/aishell/ASR/conformer_ctc/generate_CTC_label.py
+++ b/egs/aishell/ASR/conformer_ctc/generate_CTC_label.py
@@ -32,22 +32,11 @@ import torch.nn as nn
 from asr_datamodule import AishellAsrDataModule
 from conformer import Conformer
 
-from icefall.char_graph_compiler import CharCtcTrainingGraphCompiler
 from icefall.checkpoint import average_checkpoints, load_checkpoint
-from icefall.decode import (
-    get_lattice,
-    nbest_decoding,
-    nbest_oracle,
-    one_best_decoding,
-    rescore_with_attention_decoder,
-)
-from icefall.env import get_env_info
 from icefall.lexicon import Lexicon
 from icefall.utils import (
     AttributeDict,
-    get_texts,
     setup_logger,
-    store_transcripts,
     write_error_stats,
 )