diff --git a/devstack/settings b/devstack/settings
index 266db61a..f5f1f11d 100644
--- a/devstack/settings
+++ b/devstack/settings
@@ -22,7 +22,7 @@ QINLING_CONF_FILE=${QINLING_CONF_DIR}/qinling.conf
 QINLING_POLICY_FILE=${QINLING_CONF_DIR}/policy.json
 QINLING_AUTH_CACHE_DIR=${QINLING_AUTH_CACHE_DIR:-/var/cache/qinling}
 QINLING_FUNCTION_STORAGE_DIR=${QINLING_FUNCTION_STORAGE_DIR:-/opt/qinling/function/packages}
-QINLING_PYTHON_RUNTIME_IMAGE=${QINLING_PYTHON_RUNTIME_IMAGE:-openstackqinling/python3-runtime:0.0.1}
+QINLING_PYTHON_RUNTIME_IMAGE=${QINLING_PYTHON_RUNTIME_IMAGE:-openstackqinling/python3-runtime:0.0.2}
 QINLING_NODEJS_RUNTIME_IMAGE=${QINLING_NODEJS_RUNTIME_IMAGE:-openstackqinling/nodejs-runtime:0.0.1}
 QINLING_SIDECAR_IMAGE=${QINLING_SIDECAR_IMAGE:-openstackqinling/sidecar:0.0.2}
 
diff --git a/qinling_tempest_plugin/config.py b/qinling_tempest_plugin/config.py
index 706d8224..198c44b2 100644
--- a/qinling_tempest_plugin/config.py
+++ b/qinling_tempest_plugin/config.py
@@ -40,7 +40,7 @@ QinlingGroup = [
                         'publicURL', 'adminURL', 'internalURL'],
                help="The endpoint type to use for the qinling service."),
     cfg.StrOpt("python_runtime_image",
-               default="openstackqinling/python3-runtime:0.0.1",
+               default="openstackqinling/python3-runtime:0.0.2",
                help="The Python runtime being used in the tests."),
     cfg.StrOpt("nodejs_runtime_image",
                default="openstackqinling/nodejs-runtime:0.0.1",
diff --git a/qinling_tempest_plugin/functions/python/test_python_sleep.py b/qinling_tempest_plugin/functions/python/test_python_sleep.py
index b9058c09..27f4efc4 100644
--- a/qinling_tempest_plugin/functions/python/test_python_sleep.py
+++ b/qinling_tempest_plugin/functions/python/test_python_sleep.py
@@ -14,5 +14,5 @@
 import time
 
 
-def main(seconds=5, **kwargs):
+def main(seconds=4, **kwargs):
     time.sleep(seconds)
diff --git a/qinling_tempest_plugin/tests/api/test_executions.py b/qinling_tempest_plugin/tests/api/test_executions.py
index efaef199..b1bcb0ba 100644
--- a/qinling_tempest_plugin/tests/api/test_executions.py
+++ b/qinling_tempest_plugin/tests/api/test_executions.py
@@ -339,7 +339,7 @@ class ExecutionsTest(base.BaseQinlingTest):
         )
 
     @decorators.idempotent_id('2b5f0787-b82d-4fc4-af76-cf86d389a76b')
-    def test_python_execution_memory_limit_non_image(self):
+    def test_python_execution_memory_limit(self):
         """In this case, the following steps are taken:
 
         1. Create a function that requires ~80M memory to run.
@@ -390,7 +390,7 @@ class ExecutionsTest(base.BaseQinlingTest):
         self.assertEqual(4, output)
 
     @decorators.idempotent_id('ed714f98-29fe-4e8d-b6ee-9730f92bddea')
-    def test_python_execution_cpu_limit_non_image(self):
+    def test_python_execution_cpu_limit(self):
         """In this case, the following steps are taken:
 
         1. Create a function that takes some time to finish (calculating the
@@ -408,7 +408,7 @@ class ExecutionsTest(base.BaseQinlingTest):
         package = self.create_package(
             name='python/test_python_cpu_limit.py'
         )
-        function_id = self.create_function(package_path=package)
+        function_id = self.create_function(package_path=package, timeout=180)
 
         # Invoke function
         resp, body = self.client.create_execution(function_id)
@@ -486,3 +486,27 @@ class ExecutionsTest(base.BaseQinlingTest):
         self.assertEqual('success', body['status'])
         result = json.loads(body['result'])
         self.assertEqual(page_sha256, result['output'])
+
+    @decorators.idempotent_id('b05e3bac-b23f-11e8-9679-00224d6b7bc1')
+    def test_python_execution_timeout(self):
+        package = self.create_package(
+            name='python/test_python_sleep.py'
+        )
+        function_id = self.create_function(package_path=package)
+
+        resp, body = self.client.create_execution(
+            function_id,
+            input='{"seconds": 7}'
+        )
+
+        self.assertEqual(201, resp.status)
+        self.addCleanup(self.client.delete_resource, 'executions',
+                        body['id'], ignore_notfound=True)
+        self.assertEqual('failed', body['status'])
+
+        result = jsonutils.loads(body['result'])
+
+        self.assertGreater(result['duration'], 5)
+        self.assertIn(
+            'Function execution timeout', result['output']
+        )
diff --git a/runtimes/python2/requirements.txt b/runtimes/python2/requirements.txt
index d1e6381a..d28c2050 100644
--- a/runtimes/python2/requirements.txt
+++ b/runtimes/python2/requirements.txt
@@ -9,3 +9,4 @@ python-mistralclient>=3.1.0  # Apache-2.0
 keystoneauth1>=2.21.0  # Apache-2.0
 openstacksdk>=0.9.19
 oslo.concurrency>=3.25.0  # Apache-2.0
+psutil>=5.4.7 # BSD
diff --git a/runtimes/python2/server.py b/runtimes/python2/server.py
index e2558bcf..f129497a 100644
--- a/runtimes/python2/server.py
+++ b/runtimes/python2/server.py
@@ -27,6 +27,7 @@ from flask import request
 from flask import Response
 from keystoneauth1.identity import generic
 from keystoneauth1 import session
+import psutil
 import requests
 
 app = Flask(__name__)
@@ -34,6 +35,7 @@ app = Flask(__name__)
 DOWNLOAD_ERROR = "Failed to download function package from %s, error: %s"
 INVOKE_ERROR = "Function execution failed because of too much resource " \
                "consumption"
+TIMEOUT_ERROR = "Function execution timeout."
 
 
 def _print_trace():
@@ -73,6 +75,17 @@ def _get_responce(output, duration, logs, success, code):
     )
 
 
+def _killtree(pid, including_parent=True):
+    parent = psutil.Process(pid)
+    for child in parent.children(recursive=True):
+        print("kill child %s" % child)
+        child.kill()
+
+    if including_parent:
+        print("kill parent %s" % parent)
+        parent.kill()
+
+
 def _invoke_function(execution_id, zip_file_dir, module_name, method, arg,
                      input, return_dict, rlimit):
     """Thie function is supposed to be running in a child process.
@@ -146,6 +159,7 @@ def execute():
     auth_url = params.get('auth_url')
     username = params.get('username')
     password = params.get('password')
+    timeout = params.get('timeout')
     zip_file_dir = '/var/qinling/packages/%s' % function_id
     rlimit = {
         'cpu': params['cpu'],
@@ -206,25 +220,31 @@ def execute():
     return_dict['success'] = False
     start = time.time()
 
-    # Run the function in a separate process to avoid messing up the log
+    # Run the function in a separate process to avoid messing up the log. If
+    # the timeout is reached, kill all the subprocesses.
     p = Process(
         target=_invoke_function,
         args=(execution_id, zip_file_dir, function_module, function_method,
               input.pop('__function_input', None), input, return_dict, rlimit)
     )
+
+    timed_out = False
     p.start()
-    p.join()
+    p.join(timeout)
+    if p.is_alive():
+        _killtree(p.pid)
+        timed_out = True
 
     ####################################################################
     #
-    # Get execution output(log, duration, etc.)
+    # Get execution result(log, duration, etc.)
     #
     ####################################################################
     duration = round(time.time() - start, 3)
 
     # Process was killed unexpectedly or finished with error.
     if p.exitcode != 0:
-        output = INVOKE_ERROR
+        output = TIMEOUT_ERROR if timed_out else INVOKE_ERROR
         success = False
     else:
         output = return_dict.get('result')
diff --git a/runtimes/python3/requirements.txt b/runtimes/python3/requirements.txt
index d1e6381a..d28c2050 100644
--- a/runtimes/python3/requirements.txt
+++ b/runtimes/python3/requirements.txt
@@ -9,3 +9,4 @@ python-mistralclient>=3.1.0  # Apache-2.0
 keystoneauth1>=2.21.0  # Apache-2.0
 openstacksdk>=0.9.19
 oslo.concurrency>=3.25.0  # Apache-2.0
+psutil>=5.4.7 # BSD
diff --git a/runtimes/python3/server.py b/runtimes/python3/server.py
index 1e9e939e..28ba3455 100644
--- a/runtimes/python3/server.py
+++ b/runtimes/python3/server.py
@@ -27,6 +27,7 @@ from flask import request
 from flask import Response
 from keystoneauth1.identity import generic
 from keystoneauth1 import session
+import psutil
 import requests
 
 app = Flask(__name__)
@@ -34,6 +35,7 @@ app = Flask(__name__)
 DOWNLOAD_ERROR = "Failed to download function package from %s, error: %s"
 INVOKE_ERROR = "Function execution failed because of too much resource " \
                "consumption"
+TIMEOUT_ERROR = "Function execution timeout."
 
 
 def _print_trace():
@@ -73,6 +75,17 @@ def _get_responce(output, duration, logs, success, code):
     )
 
 
+def _killtree(pid, including_parent=True):
+    parent = psutil.Process(pid)
+    for child in parent.children(recursive=True):
+        print("kill child %s" % child)
+        child.kill()
+
+    if including_parent:
+        print("kill parent %s" % parent)
+        parent.kill()
+
+
 def _invoke_function(execution_id, zip_file_dir, module_name, method, arg,
                      input, return_dict, rlimit):
     """Thie function is supposed to be running in a child process.
@@ -146,6 +159,7 @@ def execute():
     auth_url = params.get('auth_url')
     username = params.get('username')
     password = params.get('password')
+    timeout = params.get('timeout')
     zip_file_dir = '/var/qinling/packages/%s' % function_id
     rlimit = {
         'cpu': params['cpu'],
@@ -212,8 +226,13 @@ def execute():
         args=(execution_id, zip_file_dir, function_module, function_method,
               input.pop('__function_input', None), input, return_dict, rlimit)
     )
+
+    timed_out = False
     p.start()
-    p.join()
+    p.join(timeout)
+    if p.is_alive():
+        _killtree(p.pid)
+        timed_out = True
 
     ####################################################################
     #
@@ -224,7 +243,7 @@ def execute():
 
     # Process was killed unexpectedly or finished with error.
     if p.exitcode != 0:
-        output = INVOKE_ERROR
+        output = TIMEOUT_ERROR if timed_out else INVOKE_ERROR
         success = False
     else:
         output = return_dict.get('result')