The structure of social network and its information spreading characteristics in 41 users of Sina microb-logs were studied , which showed that the exchange level was quite low in the 41 users of health information in Sina microblogs, usually in small groups.Although the 41 users were found in the core area, their exchange was sporadic even with no exchange in the core nodes or in other nodes, thus effective information sharing could not be achieved and information could not be widely spread .

The effect of cognition need on information seeking behaviors of information users and the difference in behaviors of information users were investigated in 184 undergraduates from the same grade with different back-grounds of subjects using the cognition need scale and undergraduates information-seeking behaviors scale ,respec-tively.The data were analyzed by descriptive statistical analysis, correlation analysis, rank test, and multivariate linear regression analysis , respectively , showing that the cognition need is significantly correlated with the informa-tion seeking behaviors of undergraduates in terms of information evaluation, information searching, information management and information use .