There is always a concern about bubble in the development of Chinese real estate market. Recently, with the increase of housing price, discussion in the regard is getting more attention. If the bubble bursts, it will cause great damage to Chinese economy and society. Thus, it has significant practical meaning to prevent real estate bubble. In this paper it analyzes the rent-sale price ratio in China. It indicates that the housing price in current China is too high; much of the housing demand is investment and speculation; and bubble exists in real estate market. In this paper, it further discusses the reasons of unbalanced rent-sale price ratio and puts forward some suggestions.