The present paper, taking Chang Jung Christian University (CJCU) Library as an example, investigates the users' degree of importance and the performance provided by the library. This study explores overall user satisfaction as well. A questionnaire survey is conducted to reveal users' perspectives on service quality. Based on literature, service quality has five dimensions, which are tangibles, responsiveness, reliability, assurance, and empathy. The results indicate that the overall service quality has a significantly positive effect on overall user satisfaction. Among these five dimensions except responsiveness, all of them have a significantly positive effect on overall user satisfaction. In addition, the top five important service quality features ranked by users are: collections, loaning and returning service, overall atmosphere, electronic database system, and online reservation and renewal. Furthermore, the perceived importance of service quality dimensions has no significant difference among institutes and status.