Originally Posted by Arlene Lee

If you've added an AdSense for search box to your page, you're probably aware of the relevant search results it provides your users. That being said, a few publishers have asked us if it’s a violation of our program policies to perform searches in their own AdSense for search boxes. The short answer is no, this activity is not explicitly prohibited by our program policies.

However, we strongly advise against using your own AdSense for search box for a couple of reasons. First, it can increase the chance of accidental or invalid clicks on the ads that appear on the search results pages. Second, this will inflate the number of queries in your reports, giving you an inaccurate picture of the activity on your site.

If you’d like to use Google search, we recommend visiting Google.com or installing the Google Toolbar. And if you're using Google Chrome, don't forget that you can type search queries directly into your address bar.