In this paper, we investigate generation process of vacant housing. And we analyze that how real estate prices are affected by aging. We run regional panel regressions for Japan. Our regression results show that, in Japan, real estate prices in a region are inversely correlated with the old age dependency ratio, i.e. the ratio of population aged 65 +to population aged 20-64, in that region, and positively correlated with the total number of population in that region. The demographic factor had a greater impact on real estate prices in Japan. Based on the regression result for Japan and the population forecast made by a government agency, we estimate the demographic impact on Japanese housing prices over the next 30 years. We find that it will be -2.4 percent per year in 2012-2040, suggesting that aging will continue to have downward pressure on land prices over the next 30 years. In addition to population decline and aging problem, we will also face aging problem of housing stock, especially for condominiums.