Abstract: This paper took the users who are under the tag of entertainment in Sina microblog as sample.Combined with “concerning” and “concerned” relationship between users,it built “mutual-concern” network by using social network analysis,then analyzd the network respectively from degree centrality,betweenness centrality and cohesive subgroups analysis.Comparing with real data by using the given core users analysis method,it revealed the core microblogger of the tag and the relationship between network members.Experimental results indicate that the method is feasible for specific network.In the end,it put forward the corresponding enlightenments.

Key words: Social network analysis,Microblog,Centrality,Core microblogger