diff --git a/paddle/scripts/paddle_build.sh b/paddle/scripts/paddle_build.sh
index 962ee53a1069b8cd7863a0f1dca616c939eb237d..df9daa17e9f3a3520f9ffdf3fbee0b546d100678 100755
--- a/paddle/scripts/paddle_build.sh
+++ b/paddle/scripts/paddle_build.sh
@@ -1031,6 +1031,38 @@ set -ex
     fi
 }
 
+function precision_test() {
+    if [ ${WITH_TESTING:-ON} == "ON" ] ; then
+    cat <<EOF
+    ========================================
+    Running precision unit tests  ...
+    ========================================
+EOF
+
+set +x
+        EXIT_CODE=0
+        testcases=$1
+        if [[ "$testcases" == "" ]]; then
+            return 0
+        fi
+        card_test "$testcases"
+        collect_failed_tests
+        if [ -n "${failed_test_lists}" ];then
+            failed_test_lists_ult=`echo "${failed_test_lists}" |grep -Po '[^ ].*$'`
+            echo "========================================"
+            echo "Summary Failed Tests... "
+            echo "========================================"
+            echo "The following tests FAILED: "
+            echo "${failed_test_lists_ult}"
+        fi
+        rm -f $tmp_dir/*
+        if [[ "$EXIT_CODE" != "0" ]]; then
+            exit 8;
+        fi
+set -ex
+    fi
+}
+
 function parallel_test_base_cpu() {
     mkdir -p ${PADDLE_ROOT}/build
     cd ${PADDLE_ROOT}/build
@@ -1055,10 +1087,14 @@ function parallel_test() {
     mkdir -p ${PADDLE_ROOT}/build
     cd ${PADDLE_ROOT}/build
     pip install ${PADDLE_ROOT}/build/python/dist/*whl
-    if [ "$WITH_GPU" == "ON" ];then
-        parallel_test_base_gpu
+    if [ "${CASES}" != "" ]; then
+	precision_test $CASES
     else
-        parallel_test_base_cpu ${PROC_RUN:-1}
+        if [ "$WITH_GPU" == "ON" ];then
+            parallel_test_base_gpu
+        else
+            parallel_test_base_cpu ${PROC_RUN:-1}
+        fi
     fi
     ut_total_endTime_s=`date +%s`
     echo "TestCases Total Time: $[ $ut_total_endTime_s - $ut_total_startTime_s ]s"
diff --git a/tools/get_pr_ut.py b/tools/get_pr_ut.py
new file mode 100644
index 0000000000000000000000000000000000000000..6ab9dbf6214d16416d06f463171d3605a0223498
--- /dev/null
+++ b/tools/get_pr_ut.py
@@ -0,0 +1,70 @@
+#!/bin/env python
+# Copyright (c) 2020 PaddlePaddle Authors. All Rights Reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# 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.
+""" For the PR that only modified the unit test, get cases in pull request. """
+
+import os
+from github import Github
+import ut_filter
+
+
+PADDLE_ROOT = os.getenv('PADDLE_ROOT', '/paddle/')
+class PRChecker(object):
+    """ PR Checker. """
+
+    def __init__(self):
+        self.github = Github(os.getenv('GITHUB_API_TOKEN'), timeout=60)
+        self.repo = self.github.get_repo('PaddlePaddle/Paddle')
+	self.pr = None
+
+    def init(self):
+        """ Get pull request. """
+        pr_id = os.getenv('GIT_PR_ID')
+        if not pr_id:
+            print('No PR ID')
+            exit(0)
+        self.pr = self.repo.get_pull(int(pr_id))
+
+    def get_pr_files(self):
+        """ Get files in pull request. """
+        page = 0
+        file_list = []
+        while True:
+    	    files = self.pr.get_files().get_page(page)
+    	    if not files:
+    	        break
+    	    for f in files:
+    	        file_list.append(PADDLE_ROOT +  f.filename)
+    	    page += 1
+        return file_list
+        #return ['/paddle/paddle/fluid/memory/malloc_test.cu']
+
+    def get_pr_ut(self):
+        """ Get unit tests in pull request. """
+	ut_str = ''
+        ut_mapper = ut_filter.UTMapper()
+	file_ut_map = ut_mapper.get_src_ut_map()
+	for f in self.get_pr_files():
+	    if f not in file_ut_map:
+		return ''
+	    else:
+		ut_str = '{}^{}$|'.format(ut_str, file_ut_map[f])
+	return ut_str.rstrip('|')
+
+
+if __name__ == '__main__':
+    pr_checker = PRChecker()
+    pr_checker.init()
+    print(pr_checker.get_pr_ut())
+
diff --git a/tools/ut_filter.py b/tools/ut_filter.py
new file mode 100644
index 0000000000000000000000000000000000000000..47fdad5b1b855c2f0934f00fa315f9093e7ad905
--- /dev/null
+++ b/tools/ut_filter.py
@@ -0,0 +1,74 @@
+#!/bin/env python
+# Copyright (c) 2020 PaddlePaddle Authors. All Rights Reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# 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.
+""" Build file and unit test mapping. """
+
+import os
+import re
+import json
+import time
+import os.path
+import subprocess
+from github import Github
+
+
+PADDLE_ROOT = os.getenv('PADDLE_ROOT', '/paddle/')
+
+class UTMapper(object):
+    """ Unit test mapper. """
+
+    def __init__(self):
+        self.github = Github(os.getenv('GITHUB_API_TOKEN'), timeout=60)
+        self.repo = None
+	self.ut_list = []
+	self.src_ut_dict = {}
+
+    def load_ctest_ut_list(self):
+        """ Load ctest unit test list. """
+	ps = subprocess.Popen("ctest -N | awk -F ':' '{print $2}' | sed '/^$/d' | sed '$d' | sed 's/ //g'", 
+		shell=True, stdout=subprocess.PIPE, stderr=subprocess.STDOUT, cwd='{}build'.format(PADDLE_ROOT))
+	uts = ps.communicate()[0]
+	self.ut_list = uts.rstrip('\n').split('\n')
+
+    def load_cpp_and_cuda_ut(self):
+        """ Load C++ and CUDA unit test list. """
+	data = None
+	cpp_cuda_ut_file = '{}build/compile_commands.json'.format(PADDLE_ROOT)
+	with open(cpp_cuda_ut_file) as f:
+	    data = json.load(f)
+	for ut in data:
+            ut_name = re.search('-o .*\/(.*).dir\/.*', ut['command']).group(1)
+	    if ut_name not in self.ut_list:
+		continue
+	    self.src_ut_dict[ut['file']] = ut_name
+
+    def load_python_ut(self):
+        """ Load Python unit test list. """
+	pyut_files = subprocess.check_output('find {}python -name test*.py'.format(PADDLE_ROOT).split(' '))
+	pyut_list = pyut_files.rstrip('\n').split('\n')
+        for src_file in pyut_list:
+	    self.src_ut_dict[src_file] = src_file.split('/')[-1].split('.py')[0]
+
+    def get_src_ut_map(self):
+        """ Get src file and unit test map. """
+    	self.load_ctest_ut_list()
+        self.load_cpp_and_cuda_ut()
+        self.load_python_ut()
+	return self.src_ut_dict
+
+
+if __name__ == '__main__':
+    ut_mapper = UTMapper()
+    ut_mapper.load_python_ut()
+    ut_mapper.load_ctest_ut_list()