Taking short message service (SMS) used widely by individual consumers under mobile environment as the object, the factors influencing the usage behaviors of consumers in SMS were studied by Technology accepted model(TAM) and network externality theory and the usage behavior model for individual users in SMS was built.  The scaling of reliability and validity of the model was tested through SPSS 13.0 and the hypotheses of the structure equation model were verified by Lisrel 8.7. On the basis of the research results, corresponding countermeasures are also proposed.