Abstract: This paper analyzes present situation of wechat mobile information services in university library,and induces the function structure diagram of wechat mobile information services in university library by selecting 39 "985 project"university libraries as the research sample.and .The paper points out that wechat information ecological system in university library is composed of three parts which are the information people, university library wechat information and the information environment,and constructs the pyramid shaped university library information ecosystem model.