Abstract: Exploring the differences of citation frequency of digital library papers in different cooperation modes, and providing reference for researchers. SPSS software was used for Kruskal-Wallis test and Mann-Whitney U test. It is found that the way of paper cooperation has the following effects on cited frequency. Firstly, the citation frequencies of papers with 2 or 3 authors are significantly higher than these with only one author, and the citation frequencies are no significant difference between intra and inter unit cooperation. Secondly, in the case where the librarian is the first author, the citation frequencies of papers with cooperation between librarians and librarians are not significantly different from these between librarians and teachers.The same is true for the teacher as the first author. Thirdly, there are differences in the impact of cooperation on the citation frequency of papers at different fund levels, with significant difference for those without fund and no significant difference for those with fund. Fourthly, there are differences in the impact of the citation frequency on the papers of different grades of impact factor, with significant difference in the middle level and no significant difference at both ends.

Key words: co-authorship; cooperation; citation frequency; digital library