Objective:To research the application of State Space Model forecasting in infectious disease incidence,and discuss the method to improve its veracity and practicability. Methods:A model was fitted by the historical data of the incidence of tuberculosis in China. Firstly,used the ratio to moving average method and HP filter to make preanalysis. Secondly,parameters of model is estimated and a State Space Model was set up by decison of the rank of it. Finally,the paper tests the result of forecast and analysis it. Results:State Space Model can decompose some characteristic components from the changing process of the incidence. Forecast accuracy of the Monthly incidence in a year is above 90%. Conclusion:The fit values of incidence are consistent with the actual data of incidence and the forecasting effect is good.