This study means to show the geographecal characteristics of mental hospitals' positions and their historical change. The way of study is to analyze the city area conditions of mental hospitals and their change in Tokyo. As a conclusion, mental hospitals are likely to be built in the outerskirts. Expectionally, they had been in the city area before 1920. Secondly, the hospital has been in the city area even if we have urbanization there. Thired, in each decade of these hosipals foundation in Tokyo, They have been classified into 4 types. As the times have gone by, they have moved to the west.
