In recent years, the domestic real estate industry has achieved great progress and success. Researching on real estate bubbles has been one of the hottest issues in the field of economics. This paper, based on the BehavioralFinance theories, starts with the noise trading model. After the quote and comment on the model, this paper finds out that it is the noise traders expectations, the average value of noise traders misperceptions, risks and the proportion of noise traders that contribute to the formation of real estate bubbles. Based on the above analysis, this paper then verifies the findings based on the data of 35 cities from 2002 to 2011. Finally, it points out that the noise traders expectations is a key factor for forming the recent real estate bubbles.