How to Delete a History Log on YouTube
YouTube keeps track of every video you have ever looked at. This will appear in the drop down list when you are doing your searches. This can be a pain sometimes when trying to find something specific, but it can also be helpful when you have a favorite video you like to watch. If you do not want the list displayed because you find it a hindrance or you simply don't want someone else to know what videos you have been watching, there is a simple fix.
Sign in to your account.
Click "Account" at the top right of the page.
Under "My Videos," click the "History" option.
Click the "Viewing History" tab.
Click the "Clear Viewing History" button at the top of the video list.