There is an option that Japanese agriculture is still highly protected. Agricultural protection is classfied into fiscal experiments and market price supports. Market orice supports are defined as price differences between foreign and Japanese products. One of factors that form price differences is maintenance of high tariffs of rice and dairy products. However, tariff rates of Japanese agricultural products are already low overall. Therefore, it is difficult to explain the price differences only by tariffs. We think that some part of the price differences chan be explained by the domestic production premium, which is higher appreciation of domestic products by Japanese consumers. In this study, we neasured the component rate of each factor in agricultural protection in Japan by using the PSE date of OECD. We obtained the result that the ratio of protection by tariffs was about 56%, the ratio of the domestic production premium was about 40%, and the ratio of fascal experimentures was aout 4%, when rice and dairy prosducts were excluded.