In this paper, based on Chinese 1990—2009 GDP figures, index curve model, ARIMA model and cubic polynomial model were established, furthermore, with the error squares minimum for optimality criteria to establish the combination forecast model, and the 2010-2015 GDP value in China was predicted with these models. The results showed that the accuracy of combination forecast model is higher than that of each individual predictions model. In 2010-2015, the average annual growth rate is 14.79% , China's national economy still growing with rapid pace.