In September 2012,at the video and telephone conference of national education informatization,vice premier Liu Yandong explicitly stated to promote the project “Network learning space used by everybody”,to accelerate the revolution of teaching and learning methods and to possess all teachers and students beyond junior high school of network learning space in 5 years all so.Devote to walk in the forefront of the world in the area of network learning space construction and application[1].With the development of information technology,network learning space is increasingly used in formal and informal teaching process,in which collaborative knowledge building is bound to be more and more.Collaborative knowledge building is a synonym of "collaborative learning",but it is more than the traditional sense of knowledge acquisition.It reflects the development of individual and collective intelligence.This concept has been extensively paid attention and recognition since proposed,so from collaborative knowledge building perspective to research the learners' learning strategy on network learning space can reflect the individual development and focus on community development,in line with the direction of the instructional development in the society of knowledge.The author considers all participants who took part in the discussion area of this E-learning space as a whole.The information exchange and communication among members is simplified as the relationship network.Using the method of session analysis to record,code and analyze the contents of the conversation among learners of network learning space; using the method of social network analysis we get social interactive data of the collaborative knowledge building community and illustrate the social interactive situation in collaborative knowledge building process.At the end,this article puts forward some related strategies.