It is known that the consumption function of a country's macro economy is C = 150+0.5Y, the investment function is I = 150-400R, the transaction demand function of currency is L1 = 0.25Y, and the speculative demand function of currency is L2 = 50-100R. We know that government spending G = 50, and the real money supply M/P = 180. The equilibrium of national income Y, interest rate level R, consumption level C, investment level I, currency trading demand L1 and currency speculation demand L2 is found.