The primary purpose of this study is to understand academic library service as a brand and a set of brand offerings. Based on previous studies, the study has built a classification of three distinctive perceptual aspects of library services; perceptual aspect of the service, experiential aspect of the service, and functional aspect of service. Eleven measurement items and 45 questions that are subject to the items are studied and employed from previous studies, each of the items were allocated through Item Response Theory (IRT) test and cluster analysis to filter in items of substantial contribution to the constructs as well as filtering out less contributable ones. The study shows there are 27 effective items to understand and measure library service as a brand.