Development of online courses provides a broad space for libraries to raise their own values. Meanwhile， an accurate and objective evaluation of the teaching quality of online courses in university libraries is significant for improving the educational function of libraries. With available statistical data， we develop an evaluation index system for online course teaching quality in university libraries base on design basis for indexes and through four specific common indicators of teaching contents， teaching methods， teaching results and video qualities. Then we introduce AHP method to determine the weight of each index. The results show that our evaluation index system can truly reflect the actual situation of online course teaching quality， which can then enable us to raise existing problems and corresponding suggestions.