We studied modern political history of Tama area through analysis of a general election from the first time(1890) to 36th(1980). Peoples of Tama area have much influenced political scenes by Freedom and People’s Right movement, by the Constitutional Seiyukai Party. The Constitutional Seiyukai Party opposed universal suffrage movement from premature position of Takashi Hara. In spite of growing the proletarian party, they accelerated trend forward militarism in early Showa era. They made a complete change to support radical party especially the Socialist Party after World WarⅡ. Radical parties gained a majority of comparative rate of votes in Tama area in the 1960s. And they supported Minobe’s radical government of Tokyo. After the 1960s increasing of many parties, in 1980s for example, Naoto Kan was returned to the Diet and civic parties made rapid progress after that they brought the change of political power. In conclusion, voters of Tama area changed modern Japanese political history in many scenes.