google doesn't show all the back links of your site. yahoo does you can see all your back links in google if you use webmaster tool.
Do you have a Google Webmasters account? That is where you can find all backlinks to your site as the link:// command in Google does not show a lot of backlinks If you have none, create your Google Webmasters account http://www.google.com/webmasters/tools/
Not only does Google not show you all of the backlinks, they don't count all of them either. If you just want to see the total number of backlinks your site has, then use yahoo as other people have suggested. They aren't picky, they show everything. However, if you want to see the backlinks that Google counts towards your Google Page Rank, then you have to use Google Webmaster Central. Keep in mind that the big D discounts and disregards many, if not most, backlinks for various reasons. Just becuase you have a backlink, doesn't mean it counts towards PR.
Google doesn't shows all the backlinks when u search for the query link:www. mydomain .com[/url] Instead of that is you see the external links listed in your google webmaster tools you will get all the backlinks. hope so this will help u any how.