The purpose of this paper is to propose an analytical model for evaluating Internet Web sites, that is comprehensive and flexible enough to accomodate different categories of Internet Web sites. This paper is intended to identify critical success factors of Internet Web sites to determine criteria for evaluating the Web sites, and use the criteria to develop a framework for comprehensive evaluation of Internet Web sites. The framework consists of eight categories, including design, business functions, trustworthiness, interface, technology, community, contents, and others. An empirical study designed to validated the framework has been conducted for each of the three Web site categories, including (1) information provision, (2) product sale, and (3) customer service. The results show that ‘content ’ is the most important for information provision Web sites, ‘trustworthiness’for product sale Web sites, and ‘design’ for customer service Web sites. The framework may be used not only as a tool to evaluate Internet Web sites, but also as a checklist to improve the quality of a Web site that is under development.