In information system research. there has been a strong interest in developing the user-centered interface. Interface metaphors have been regarded as a user friendly device of the information retrieval systems. This study is to discover overall opinions about metaphors and to evaluate the usability of metaphors used in the homepages and retrieval interfaces of academic and public libraries. It is found that some metaphors cause users to confuse because they are similar each others or don`t have unique meaning and because some have weak relationship between texts and images of metaphors. It is necessary to develop a metaphor model suitable for the a specific interface. This study proposes to develop functional metaphors which can help users easily understand how to operate and remember the procedures, and which are based in user`s knowledge and experiences. The organizational metaphors of a virtual community also will be considered as a new type of retrieval interfaces.