[Purpose/significance] With the sprouting of Social Network (SNS), the structure of academic communication gets changed. The data mining and analysis for the communicated content from Social Network will help to identify the morphological structure and characteristic changes of the informal academic organization (Invisible College). [Method/process] This paper takes the example of Wu Yishan, who is the famous scholar on the field of Library and Information Science. Firstly, we analyze the friends of Wu Yishan and the friends of Wu Yishan's friends; identify the existence of Invisible College under the social network environment. Secondly, we discuss the new morphological structure and characteristics of the visible College under the social network environment from the perspective of communicative methods, staff composition and diffusion path of the knowledge. [Result/conclusion] Based on the above study, we found that there appear a new way of communication named "academic blog", the staff composition makes a leap of subjects and place and the diffusion of knowledge changes from "disorder" diffusion to "directed" diffusion.