Abstract: To improve the accuracy of clustering in Web sessions,by fully utilizing the URL path similarity,a new method of measuring similarity of sessions is proposed,viz.IPB(interest-point based).The method defines all the pages in the same content of page hierarchy as an interest point,and extracts interest points in a session.Based on the similarity of URLs path,the similarity of interest point is computed,and the similarity of sessions based on their interest points calculated.Experimental(results,) compared with the previous methods,show that the proposed method is more accurate in(measuring) similarity of sessions.