We proposed a novel approach for “Evaluating Web Sites Based on GHAP”, we evaluate websites based on web usage mining and try to make the evaluation practically, so that users can easily find a good website from WWW and access to high quality data and good services that attract users. Hence, evaluation methods for the effectiveness of web sites are a critical issue in both practice and research. Also we conducted experiments and confirmed the effectiveness of our approach and its potential in performing high quality web site evaluation.