The reuse system mentioned in this paper is an overall system for realizing a reuse business in a cyclic process of design, fabrication, construction, maintenance, dismantling, and storage. This system is one of methods to reduce environmental burden in the structural field. Here, we take up rolled H-section steel used for non-fireproof plants and warehouses. These buildings are assumed to be demolished within approximately 30 years. In this paper, the authors estimate the degree of reusable members through stock investigation of low-storied structure using rolled-H section steel. Classified figures of these structures, structural members and joints method, performance of structural members are shown. Then, characteristics materials of structural steel are estimated in each production year.