diff --git a/samples/client_keepalive.py b/samples/client_keepalive.py
index d175202..3e45f7f 100644
--- a/samples/client_keepalive.py
+++ b/samples/client_keepalive.py
@@ -2,6 +2,12 @@ import logging
 from hbmqtt.client._client import MQTTClient
 import asyncio
 
+#
+# This sample shows a client running idle.
+# Meanwhile, keepalive is managed through PING messages sent every 5 seconds
+#
+
+
 logger = logging.getLogger(__name__)
 
 config = {
diff --git a/samples/client_subscribe.py b/samples/client_subscribe.py
index bdbb689..da667b5 100644
--- a/samples/client_subscribe.py
+++ b/samples/client_subscribe.py
@@ -2,6 +2,13 @@ import logging
 from hbmqtt.client._client import MQTTClient
 import asyncio
 
+
+#
+# This sample shows how to subscbribe a topic and receive data from incoming messages
+# It subscribes to '$SYS/broker/uptime' topic and displays the first ten values returned
+# by the broker.
+#
+
 logger = logging.getLogger(__name__)
 
 C = MQTTClient()
@@ -9,12 +16,15 @@ C = MQTTClient()
 @asyncio.coroutine
 def test_coro():
     yield from C.connect(uri='mqtt://iot.eclipse.org:1883/', username=None, password=None)
-    ret = yield from C.subscribe([
+    # Subscribe to '$SYS/broker/uptime' with QOS=1
+    yield from C.subscribe([
                  {'filter': '$SYS/broker/uptime', 'qos': 0x01},
              ])
     logger.info("Subscribed")
-    logger.info(repr(ret))
-    yield from asyncio.sleep(10)
+    for i in range (1,10):
+        ret = yield from C.deliver_message()
+        data = ret.packet.payload.data
+        logger.info(str(data))
     yield from C.unsubscribe(['$SYS/broker/uptime'])
     logger.info("UnSubscribed")
     yield from C.disconnect()
@@ -22,5 +32,5 @@ def test_coro():
 
 if __name__ == '__main__':
     formatter = "[%(asctime)s] {%(filename)s:%(lineno)d} %(levelname)s - %(message)s"
-    logging.basicConfig(level=logging.DEBUG, format=formatter)
+    logging.basicConfig(level=logging.INFO, format=formatter)
     asyncio.get_event_loop().run_until_complete(test_coro())
\ No newline at end of file