In modern era people get more and more dependent on internet for every type of information. To extract user's interested access pattern of web click stream data, Web Usage Mining is an application of this type of techniques. Record of different web user's web using pattern are get stored in web log repository, which are great source of knowledge about user's navigation. With increasing the use of internet, number of web sites and web pages are increasing rapidly so web usage mining become problematic for many application such as design, personalization, analysis of traffic, usability-studies,...