The library is a social institution that should ensure all users' information access rights. In this study, the concept of universal design is analyzed as a theoretical basis that library Websites should be accessed equitably by all kinds of users, and an evaluation criteria is developed based on the principles of universal design. The Websites of 7 regional central libraries are evaluated with suggested criteria and the ratio of compliance of universal Web design is measured. In the result, the most of the Websites are showed not only high performances on the area of (1) Web accessibility and (2) usability, but low performances on the area of (1) equitable use and (2) flexibility in use.