Abstract: The sub-prime mortgage loan crisis which took place in the United States in 2007 has swept the globe rapidly,causing the rate of China's foreign trade growth to slow down. The expansion of the domestic demand goes into the outlook of people once again and becomes a hot topic.This paper analyzes the characteristics of the domestic economic development over the past decade,points out the status of the consumption demand in China's aggregate demand and puts forward the causes of the insufficient consumption and the corresponding measures from the consumption power,the consumer confidence,the industrial structure,the middle class and other aspects,particularly emphasizing the role of the middle class in expanding domestic consumption demand.