The purpose of this study was to measure performance of university libraries, especially investigating the components of service quality and their relationship to the customer satisfaction. The result of the study was summarized as follows: First, the factors on satisfaction of library service revealed 12 factors such as access of information, quality of employees, suitable collections, issues related to civil petitions, equipments and facilities, timeliness, operating hours, use of information technology, library user education, reference service, public relation and individual service. Second, the factors of library service on customer satisfaction showed the following primary factors: suitable collections, issues related to civil petitions, access of information, equipments and facilities, timeliness, public relation, reference service, operating hours, and individual service. Third, the components of library service on customwe satisfaction showed the following primary components: availability, the number of books and journals, facilities of air conditioning, public relation, usefulness of retrieval system, waiting time for Internet use, operating hour, speed of repairs, receipt of civil petitions, use of non-book materials.