Research papers on sevice quality, which began with the manufacturing industry in many Northern Europe at the end of 1970, have been found since the companies became much concerned about the level of services they offered. Libraties can not be an exception to this situation. It is absolutely necessary to find a way to develop a competitive strategy to offer a high level of service to those who use libraries. The purpose of study is to evaluate the quality of library services by applying "SERVQUAL" and "SERVPERF" of evaluating service quality and to determine which of these 2 methods is better in terms of measuring library services. The study also investigated the relationship between the service quality an user satifaction.