This paper clarifies factors of the difference in the ratio of three-generation households. The conclusions are as follows. 1. Classification with high ratio of three-generation households has many municipalities that ratio of inhabitable area and cultivated area are high. 2. Classification with low ratio of three-generation households has many municipalities that ratio of inhabitable area and cultivated area are low. 3. Many city parts are in high ratio of inhabitable area and low ratio of cultivated area.