The purpose of this study is to investigate asymmetric and nonlinear nature of the relationship between service attributes and global customer satisfaction, and to identify improvement strategies of service quality in libraries. In this study, two methods(such as kano's analysis and importance grid) were used to analyze the factor structure of customer satisfaction in libraries. The results show that two quality elements are classified as excitement factors, twelve quality elements are sorted as hybrid factor and eight quality elements are classified as dissatisfiers.