The growth of Web site is incredible. Nowadays, the Web resources became an important information source for library users. Many libraries provide Web resources as links on their Web pages. Did they filter or evaluate these infomration ﹖ Without explicit criteria for selection of there resources, libraries risk wasting patrons' time with tools of dubious value. Topics discussed in this article include:1. the relationship between Web resources and libraries, 2.the characteristics of Web resources, 3.the significance of Web sites evaluatiion, 4. who can be the evaluator, 5.the distinction of various evaluation activites, 6. the evaluation criteria of library, and 7.rating the ratings.