The study describes an architectural survey of OKURA MUSEUM OF ART designed by Chuta Ito. We made surveys about the materials, the structures and the building constructions. This study will be a reference example for architects and constructers who work on conservation repair work of modern architectures. Result of surveys, we found the concrete compressive strength is adequate but the concrete neutralization is progressing. OKURA MUSEUM building has a roof slab and steel shutters, steel window sashes. These improve fire resistance. We had found that concatenation of rooftops and restoration of corbels will be the subjects of future conservation repair work.