Social network analysis was performed on 545 job descriptions in 32 university libraries in Seoul, and drew the job distribution and their relations. Furthermore, for finding the differences according to scale of libraries, this study performed secondary analysis by dividing them two groups. Results show that large scale library show lower density and loose connectivity than small scale library. And while jobs of small scale library were clustered 3 groups, large scale university cluster 4 groups containing 1 technical job and 3 diverse user services. And the jobs that has high specificity, such as catalog or classification, shows high degree centrality in the case of small scale library. Whereas in large scale library they show lower degree centrality, so it can be said that these jobs were performed somewhat independently in large scale libraries.