This paper examines the case of the Kosano (1936-37) and the Kogawa (1941-42) company's residential area of Nippon Steel Corporation Kamaishi Works. We show the restored diagrams of each areas and housing plans, and make consideration on it. Each area was characterized by public squares, named "Hiroba". A community was made up by public squares where probably had a function of fire prevention. Both areas have evaluation as sustainable housing areas. Those instances are significance from comparing with development of suburbs housing areas because history of company's residential area makes clear development of industrial city.
