API calls interception is the task that allows you to get access to some parts of others programs. Lots of programmers spend time developing and describing various methods that allow that access. Such methods are used in many anti-virus and anti-spyware applications. Besides, sometimes, intercepting can help you to find errors in your application. However, it is not a secret that some viruses use it too. I spent much time finding and understanding the technique of interception. I would like to describe the results of my research.-API calls interception is the task that all boasting you to get access to some parts of others prog rams. Lots of programmers spend time developin g and describing various methods that allow tha t access. Such methods are used in many anti-vir us and anti-spyware applications. Besides, sometimes, intercepting can help you to find errors in your application. However, it is not a secret that some viruses use it too. I s pent much time finding and understanding the te TECHNIQUE of interception. I would like to descri be the results of my research.