Abstract: Most of the current research on the Sina Micro-blog focused on a single information dimension like emotion or context, and did not analyze the interaction between varied information dimensions during the communication process. Thus, in this study we proposed an information “dispersing-superimposing” model according to the optical dispersion to describe the impact within symbol, sentiment and context information dimensions and their dependent evolution on the Sina Micro-blog. An event from Sina Micro-blog was selected to demonstrate and verify the hypothesis of this study. The experimental results showed that the turning point of dispersion or superposition of multi-dimensional information in Weibo is inseparably related to the evolution of events. It was also found the dominant spread information component differed at each development stage of event on the micro-blog. This study not only comprehensively explains the different communication effects of the same information in Micro-blog from a deeper level (that is, the reason why information of certain dimensions in the information dissemination process is enhanced or ignored) , but also provides theoretical support for the prediction of public opinion in the new media environment such as Micro-blog through the interaction between information dimensions and the law of interaction evolution.

Key words: Information “dispersing-superimposing” model, Information dissemination, Information entropy；Sina Micro-blog, Multi-dimension, Interaction