Housing price and its regulation are hot issues in China’s economy and society at present． However，little literature in the comprehensive study of such issue is seen either in China and abroad． Based on whether the“Quantity Limitation Protocol”takes effect，this paper builds two general equilibrium models in the housing market． The results show that，on the one hand，when the quantity limit is not effective，and when other things equal，the harsh policy on housing mortgage tends to decrease the market equilibrium housing price (some other conditions must be met as well) if the economy of scale is decreasing or constant in the composite good sector． On the other hand，when the quantity limit is effective，both the down payment ratio and the quantity limit would affect the equilibrium housing price in the market in a complex manner． Only when the down payment ratio is not too large and the economy of scale is increasing in the composite good sector，can the real estate regulatory policies effectively decrease the market equilibrium housing price when the down payment ratio falls into a particular region．