Sunuiyamutaki Stone Gate located in Naha city, Okinawa prefecture, is a typical Okinawan historic building. The present gate is a reconstructed one, because the original one built in 1519 was destroyed in World War II. When the present one was constructed in 1956, some original fabric which had survived was left on the earth behind the gate. In 1981, it was decided to reconstruct the gate again, reusing the surviving original fabric to as great an extent as possible. Thus, the conservation treatment of the original fabric was planned and actually done. This paper discusses the treatment of the original stone roofs which are made of limestone. The stones had many holes which were filled with soil and in which many plants were living. A great amount of mosses also inhabited the surface of the stones. The stones themselves had become fragile to some extent. Therefore, the conservation treatment was made as follows: 1) Cleaning. All plants, soil and mosses were eliminated by washing the stones with water and rubbing them with wire brush. 2) Consolidation and hydrofugation. The stones were impregnated by pouring a solution of an oligomer of methyl tri-ethoxy silane in organic solvent (Content 28% as silica). The amount of the impregnated solution was 7-8 kg/m². 3) Filling up the holes. The holes were filled with small granules of the same type lime stone. Then they were impregnated with a mixture of acrylic resin (Paraloid B-72) and the above mentioned silane solution. The level of the filled parts were made 5 to 10 mm lower than their surrounding original stone. One year after the treatment, the color of the surface of the filled parts became quite close to their surrounding original stone because of the natural color change of the lime stone granules due to contact with air, though it was fresh whity yellow just after the treatment.