Abstract: The influence of social network is closely related with its structural characteristics. Based on the data from Sina microblog, the distributions of the number of followers and followings were analyzed and found that the number of followers and followings both were power-law distributed. The distance characteristic between different pairs of nodes was discussed, and it was found and proved that there was "small-world" phenomenon in the microblog network. At last, the links between nodes in the network were investigated and found that the formation of the link satisfied triple closure principle. The investigation results on the above three topics are important for us to explore the relationship between the influence of micro-blog and the structural characteristics of its underlying social network, as well as to the design of mechanisms to control the influence.

Key words: influence, power law distribution, small-world, triple closure

摘要： 社交网络的影响力与其自身的结构特征密切相关。基于新浪微博的数据，对用户的粉丝数、关注数的分布及这些特征之间的关系进行分析，发现用户的粉丝数、关注数、微博数都符合幂律分布；探讨了节点之间的距离特征，发现并证明了微博网络中存在着“小世界”现象；研究了节点之间的链接形成问题，发现链接的形成满足三元闭包原理。以上三方面研究结果，对于探索微博影响力同底层社交网络结构特征的关系、设计微博影响力控制机制具有重要的意义。

关键词: 影响力, 幂律分布, 小世界, 三元闭包