The Diocese of Harbin covered Northeast China, including the present-day provinces of Inner Mongolia, Heilongjiang, Jilin and Liaoning.
Area churches were originally incorporated into the Vladivostok Diocese in 1907. The Diocese of Harbin was organized as a Metropolis in 1922 by the Church Abroad. In 1945 when the Diocese joined the Moscow Patriachate, it was reorganized as the Metropolis of Harbin and East Asia which included the Korean Mission. In 1946 it was decreed as the East Asian Exarchate. The Exarchate was abolished in 1954.