diff --git a/README.md b/README.md
index 7468036..7fe243a 100644
--- a/README.md
+++ b/README.md
@@ -3,4 +3,10 @@ website rank crawler
 
 Fetch google PR, sogou PR, baidu rank, alexa rank of a website.
 
-[http://www.lijiejie.com](http://www.lijiejie.com)
\ No newline at end of file
+Written in python.
+
+[http://www.lijiejie.com](http://www.lijiejie.com)
+
+dependencies :
+
+urllib2, sys, re, cookielib
diff --git a/siteRank.py b/siteRank.py
index 13b31d9..87b6a67 100644
--- a/siteRank.py
+++ b/siteRank.py
@@ -1,11 +1,14 @@
-#encoding=utf-8
+# website crawler and ranker
+# shows google PR, sogou PR, baidu rank, alexa rank of a website
+# encoding=utf-8
 
+# necessary dependencies
 import urllib2
 import sys
 import re
 import cookielib
 
-
+# webpage crawler and ranker logic
 class RankCrawler():
     def __init__(self, site):
         self.site = site.strip()
@@ -57,4 +60,4 @@ def run(self):
     print '%s www.site.com' % sys.argv[0]
     sys.exit(0)
 else:
-    RankCrawler(sys.argv[1]).run()
\ No newline at end of file
+    RankCrawler(sys.argv[1]).run()