Following are the factors on which your site ranking depends on. Google, Yahoo, MSN and many more search engine consider this factors to determine page rank

• The number of other sites linking to it
• The content on the pages
• The updates we make to our database
• The testing of new product versions
• The discovery of additional sites
• Changes to the search algorithm—and other factors

So to improve your site ranking, concentrate on above points and make appropriate changes

Some other factors which may help you to get better page rank:

• Original and unique content of genuine value
• Pages designed primarily for humans, with search engine considerations secondary
• Links intended to help people find interesting, related content, when applicable
• Metadata (including title and description) that accurately describes the contents of a web page
• Good web design in general