Abstract: This paper applies DEA method to measure journal knowledge exchange efficiencies of library and information journals, by establish the evaluation index system of input and output. And then uses the Tobit regression model to evaluate the correlation between the knowledge exchange efficiency and various factors. The results shows that knowledge exchange efficiency vary widely among different journals; scale is high but the crste needs to be improved; journal of scale exist marginal to efficiency; journal of communication channels、regional coverage、international spread deeply influence knowledge exchange efficiency. At last, we put forward corresponding suggestions basing on the results.