diff --git a/data/librispeech/librispeech.py b/data/librispeech/librispeech.py
index d963a7d5..a485904a 100644
--- a/data/librispeech/librispeech.py
+++ b/data/librispeech/librispeech.py
@@ -12,12 +12,12 @@ from __future__ import print_function
 import distutils.util
 import os
 import sys
-import tarfile
 import argparse
 import soundfile
 import json
 import codecs
 from paddle.v2.dataset.common import md5file
+from data_utils.utility import download, unpack
 
 DATA_HOME = os.path.expanduser('~/.cache/paddle/dataset/speech')
 
@@ -59,33 +59,6 @@ parser.add_argument(
 args = parser.parse_args()
 
 
-def download(url, md5sum, target_dir):
-    """
-    Download file from url to target_dir, and check md5sum.
-    """
-    if not os.path.exists(target_dir): os.makedirs(target_dir)
-    filepath = os.path.join(target_dir, url.split("/")[-1])
-    if not (os.path.exists(filepath) and md5file(filepath) == md5sum):
-        print("Downloading %s ..." % url)
-        os.system("wget -c " + url + " -P " + target_dir)
-        print("\nMD5 Chesksum %s ..." % filepath)
-        if not md5file(filepath) == md5sum:
-            raise RuntimeError("MD5 checksum failed.")
-    else:
-        print("File exists, skip downloading. (%s)" % filepath)
-    return filepath
-
-
-def unpack(filepath, target_dir):
-    """
-    Unpack the file to the target_dir.
-    """
-    print("Unpacking %s ..." % filepath)
-    tar = tarfile.open(filepath)
-    tar.extractall(target_dir)
-    tar.close()
-
-
 def create_manifest(data_dir, manifest_path):
     """
     Create a manifest json file summarizing the data set, with each line
diff --git a/data_utils/utility.py b/data_utils/utility.py
index f970ff55..e1e3b55e 100644
--- a/data_utils/utility.py
+++ b/data_utils/utility.py
@@ -5,6 +5,8 @@ from __future__ import print_function
 
 import json
 import codecs
+import os
+import tarfile
 
 
 def read_manifest(manifest_path, max_duration=float('inf'), min_duration=0.0):
@@ -33,3 +35,28 @@ def read_manifest(manifest_path, max_duration=float('inf'), min_duration=0.0):
                 json_data["duration"] >= min_duration):
             manifest.append(json_data)
     return manifest
+
+
+def download(url, md5sum, target_dir):
+    """Download file from url to target_dir, and check md5sum."""
+    if not os.path.exists(target_dir): os.makedirs(target_dir)
+    filepath = os.path.join(target_dir, url.split("/")[-1])
+    if not (os.path.exists(filepath) and md5file(filepath) == md5sum):
+        print("Downloading %s ..." % url)
+        os.system("wget -c " + url + " -P " + target_dir)
+        print("\nMD5 Chesksum %s ..." % filepath)
+        if not md5file(filepath) == md5sum:
+            raise RuntimeError("MD5 checksum failed.")
+    else:
+        print("File exists, skip downloading. (%s)" % filepath)
+    return filepath
+
+
+def unpack(filepath, target_dir, rm_tar=False):
+    """Unpack the file to the target_dir."""
+    print("Unpacking %s ..." % filepath)
+    tar = tarfile.open(filepath)
+    tar.extractall(target_dir)
+    tar.close()
+    if rm_tar == True:
+        os.remove(filepath)