This paper discribes two types of exposure test in Okinawa. One is about 10 years of field observation for SUS 304 and SUS 316 roofs to prove the corrosion perfomance of building materials used stainless steels. The other is exposure test for various kinds of stainless steel specimens attached to model structures, which simulates roof and eaves, to clarify the corrosion characteristics of them in atmosphere. There is no discernible difference in the degree of rusting between SUS 304 and SUS 316. SUS 316 however has a smaller pit depth than SUS 304. The pit depth is not seemed to increase after a few years. The superiority of SUS 316 in the pit depth in comparison with SUS 304 is also observed by the two years exposure test on the simulated roof and eaves model structure. Seawater-resistant stainless steel (20Cr-18Ni-6Mo steel) has superior corrosion resistance on the roof and eaves.