: The Influences of Librarian's Competence to Job Performance (Studies in the University Of Brawijaya's Library). Librarian's competence can be seen from his or her knowledge, interpersonal skill, and professional attitude. Librarian's competence is one of factors that support the achieving good job performance. However, an adequate number of librarians does not match the importance of librarian's competence. This study is using explanatory research by using 18 librarian as its sample and population. Data received by distributing questioners, which then analyzed with SPSS 21. Result of the research is that knowledge, interpersonal skill, and professional attitude jointly influence job performance. Knowledge and professional attitude partially influence job performance, whilst interpersonal skill partially not influences librarian's job performance in University of Brawijaya