You can enter either the actual URL of the website or the URL that is displayed on the ad for that website.
- Sign in to your account.
- On the AdSense Setup tab , click the Competitive Ad Filter link.
- Choose the appropriate product sub-tab
- Click Add / Edit Sites
- In the text box, enter the URLs of the sites whose ads you would like to filter from your site or AdSense for search results pages. Enter one URL per line. You can add up to 500 URLs.
- Save your changes
Changes to your filter list should be reflected on your site within 30 minutes.