The authenticity of foreign language textbooks is generally reflected in three aspects, the true situation, the natural language and the variety of materials. This research focused on the naturalness of the language, using two corpus which were created by the author directly. Firstly, it had calculated the pronouns` confidence interval, the confidence interval between pronouns and postpositions using the interval estimation methods in statistics. Then, Compared with the Korean listening textbooks, found the difference between them. The last, according to the results, put forward several suggestions to write Korean listening textbooks in the future. (YanBian University of China)