Two keywords in implementing Quality Management System ISO 9001:2008 are customer satisfaction and continuous improvement. Both are important and always influence each other. In the practice of library service, user satisfaction becomes an essential aspect for the library to make a continuous improvement. This means when a library puts priority on user satisfaction, it will make continuous improvement. In other words, a continuous improvement will always be made when the library concentrates on achieving user satisfaction. This study is aimed at identifying the achievement level ofuser satisfaction reached at Sanata Dharma University Library (SD UL) in the period of 2008 to 2014 and to find out continuous improvement that has been made by SDUL, especially, the result analysis on monitoring and assessing user satisfaction. This study was a survey that used descriptive method. The result of the study showed the achievement level of monitoring and assessmentof user satisfaction at SDUL in the period of 2008 to 2014 reached maximum score, that is, 3.5 to 3.8 in the scale of I to 5. Observed from the user satisfaction analysis, continuous quality improvement conducted in SDUL covered three important fields, that is, information and information access facilities, library services, and infrastucture and work environment. Keywords: library user satisfaction, collection and information access, library services, infrastructure and work environment