Abstract: With the development of online social networking sites represented by microblog,the microblogging users form some complex social networks.In order to study the factors that affect the formation of relationship among microblogging users,this paper used link prediction to analyze the relationship of micro-blogging users．Firstly,this paper studied how the features of network structure affect the formation of microblogging network．The features of microblogging attribute were also analyzed and introduced to build a link prediction model based on random forest classifier．The link prediction model was tested on a user data set collected from Sina Weibo．By comparing the prediction perfor-mance with and without the introduction of microblogging attribute features and analyzing the importance distribution of features,we found that besides the network structure features,microblogging attribute features have significant effect on the formation of user relationship,and can improve the prediction performance significantly.

Key words: Link prediction,Social network,Microblogging attribute,Random forest