Web servers log files collect activity information when a user accesses to a Web Server. In recent years, [1] the massive influx of information onto World Wide Web has facilitated user, not only retrieving information, but also discovering knowledge. However, web users usually suffer from the information overload problem due to the fact of significantly increasing and rapidly expanding growth in amount of information on the web. This increase in the size of data available through the web has made it necessary to find intelligent ways to reach the data and analysis the user behavior on it. Web data mining [2] is the application of data mining techniques in web data. Web mining is divided into three types. They are 1) Web content mining deals with the discovery of useful information from the web contents or data or documents or services, 2) Web structure mining mines the structure of hyperlinks within the web itself, and 3) web usage mining mines the log data stored in the web server.