Abstract: Money supply fluctuation gives jolt and causes harm to a developing national economy. Therefore, money supply’s stability and its control has become an important question for study in theory and practice. Suppose that it is random factors not system factors that bring about money supply fluctuation, then the appropriate range of money supply and the warning limit of fluctuation can be determined with statistical methods. It comes to the conclusion that the deviation of money supply from money demand is due to the range of [-0.18, 0.18] and if the fluctuation approaches or goes beyond range , regulation measures must be taken as soon as possible.