1) The mercury concentration in the rice undusted with mercury-fungicides may be largely related to the concentration in paddy field soil, for example, a well-drained paddy field containing 33.2 μg of mercury in 100 g of dry soil gave a rice having 30 μg of the metal per 100 g of the grain, and in the case of an ill-drained paddy field, 136 μg in the soil and 81 μg in the rice were determined respectively. 2) The amounts of mercury in wheat were extremely smaller than that in rice, that is, 1 to 1.5 μg of mercury was found in 100 g of the wheat which was harvested in a paddy field containing 33 to 47 μg of the metal in 100 g of dry soil. 3) No or trace mercury was found in some vegetables in the market. 4) Two kinds of cow’s milk were digested with our method and 2.5 and 8.5 μg of mercury in 100 g of the fresh milk were obtained respectively.