The core of equilibrium exchange rate model is to analyze the effects of basic economic factors on equilibrium exchange rate and to estimate equilibrium exchange rate according to systemic relation between equilibrium exchange rate and basic economic factors. By econometric analysis, we find that domestic investment, economic growth, usage effect of foreign investment and foreign trade are the long term determinative factors of RMB equilibrium exchange rate. The analytic outcome indicates that RMB exchange rate has entered into the relative steady development phase. In future reform, the floating bands of RMB exchange rate should be extended so as to fully reflect the trait of the managed floating of RMB exchange rate.