Abstract: Microblogging has become the important communication channel of the public opinion topics, and studying the propagation mechanism of public opinion topics in microblogging will be conducive to analyze and monitor the propagation process of public opinion topics. However it is difficult for the traditional information propagation models to describe the propagation and evolution of the public opinion topics in microblogging. This paper analyzes the information interaction mode and propagation characteristics of the public opinion topics in microblogging, and then the SCIR（Susceptible Contacted Infected Removed） propagation model of public opinion topics in microblogging is built up based on SIR model. A new node state called contacted state is introduced in this model in order to describe the public opinion topic propagation mechanism. The simulation results show that the propagation model established in this paper can well describe the propagation law of public opinion topics in microblogging.

Key words: microblogging, public opinion topics, propagation model, infectious disease dynamics

摘要： 微博是舆情话题传播的重要渠道，研究微博网络中的舆情话题传播机制，将有利于对舆情话题的传播过程进行分析与监控，而传统的网络信息传播模型却无法真实地描述微博网络中的舆情话题传播机制。针对以上问题，分析了微博网络中的信息互动模式及舆情话题的传播特点，以传染病动力学中的SIR模型为基础，通过引入一个新的节点状态——接触状态，构建了基于SCIR（Susceptible Contacted Infected Removed）的微博网络舆情话题传播模型。仿真结果表明，该模型可以很好地描述微博网络中的舆情话题传播规律。

关键词: 微博, 舆情话题, 传播模型, 传染病动力学