Time of use(Tou) price is one of the most efficient measure for modern demand side management(DSM).But a scientifically pricing is based on understanding the function of pricing mechanism and comprehensive analysis to social benefit.The authors develop a pricing model by game theory based on analysis of consumer's response to the time of-use price and analyze the pricing regulation of government for maximum social benefit.A conclusion is drawn,which suggests that government should let the electricity corporation to pricing, but just give a regulation on the average price level.