Abstract: Through an analysis of the reasons of real estate price fluctuation in Hong Kong，Japan and other two nations，the authors find out that there is a close relationship between exchange rate policy and asset price fluctuation.With deteriorating external economic environment and possible withdrawal of speculative capital，investment in real estate market will undoubtedly drop in China.Then the authors，based on the Impossible Trinity，further discuss the generative mechanism of the overheat investment in real estate market in the context of current exchange rate policy.It is pointed out in the end that constant exchange rate regime，better economic structure and extended investment and financing channel can，to a certain degree，prevent major rises and falls of real estate market and harmonize foreign exchange rate policy and domestic economic development.

Key words: real estate, exchange rate regime, predicament, the Impossible Trinity, refugee capital, financial market