Green spaces in residential areas have various functions, such as for recreational activities, making the place beautiful and so on. In this research, we investigated the economic effect of green spaces on the land prices in the residential area of Sapporo City, through an environmental economics technique. Factors contributing to the formation of the posted land price for the residential area in Sapporo City were identified by the hedonic approach. Results showed that the size of the nearest park or the ratio of green space surrounding the land contributed to the formation of the land price in addition to the area, shape, zoning and the access conditions such as the distance to the closest station and school. Therefore, the building and conservation of green spaces seems to be one clear option for raising the asset value of the residential area.