The purpose of this paper is to clarify the historical changes of housing policies by Hitachi, Ltd. in the company town Hitachi-city, focusing on company-owned apaitments and dormitories, and to grasp the actual conditions or utilization of old sites of them. We conducted surveys on the details of the documents about construction, demolition and conversion of Hitachi company-owned apartments and dormitories and implemented interviews, in association with Hitachi-Life, Ltd. Our results clarified the followings: 1) we recognize close collaborations of Hitachi-city and Hitachi Ltd. in enforcing the housing policies, particularly both in the post-World War II period when Hitachi-city and Hitachi Ltd. jointly supplied housing to cope with the serious housing shortage, and in the high-growth period when Hitachi Ltd. follow the government's housing policy that promotes home ownership by providing housing loan and suburban detached house estates: 2) company-owned apaitnients and dormitories were mostly constructed along with factories, but their construction were implemented in a stepwise manner in accordance with the expansion of production scale in core factories: 3) there are still lots of company-owned apartments and dormitories around new or large factories, and the rate of vacancy varies a lot: 4) as for the utilization of old sites, detached house estates were developed at good locations around factories, and commercial facilities were developed alongside arterial roads.