The aging problem characterizes the present demographic age structure and becomes an important macro factor in decision making of policymakers，which attracts a wide attention of researchers in various fields. House market is another important and popular issue. We make an attempt to explore what causes these different phenomena and whether demographic age structure is the key factor of long-term trend in house market in USA，Japan and China respectively. Using the state-level data of US from 1975 to 2010，Japan county samples from 1980 to 2010 and provincial data from 2002 to 2013 in China，we conduct a linear and panel data estimate to analyze influences of total dependency ratio，youth dependency ratio，old age dependency ratio and urbanization? ratio on house price changes respectively. The results show that effects of demographic structure change on house prices exert periodical differences in Japan，the United States and China. Urbanization ratio is the main reason for different influences of population structure in China，Japan，and the United States. Specifically，youth dependency ratio has a negative correlation with real estate asset price in USA，Japan and China. When it comes to old age dependency ratio，results differ in three countries where dependency ratio and hose price are negatively correlated in Japan and China significantly，while in America it is positively correlated. Finally，we propose some policy recommendations with respect to stable real estate price in China.