It is established a model for information spreading over the social network originating from the SEIR model of the dynamics of infectious diseases.Analyses are given with the model on the effect of the propagation mechanism and network parameters on the processes of information spreading

based on the users' behavior characterization dynamic evolution equations are deduced and the temporal evolution rules of the processes of information spreading are elaborated.The results of simulation experiment show that the SEIR-based model presented is capable of reflecting the tendency and describing the processes of information spreading over the SNS.