Natural origin heavy metal is widely distributed in Japan. Especially high heavy metal accumulated areas are relative to mining activity, geothermal activity, and rock composition such as serpentine or marine sediments. Therefore heavy metal pollution also occurred naturally. Several hundred of surface soils were collected in Miyagi prefecture based on land classification map of soil. The heavy metal distribution in surface soil significantly depends on the chemical composition of host rock and the watersheds of some specific river. Based on leached arsenic species and bulk contents of soils, the arsenic risk level for human or plant were calculated by the accumulation from some exposure process from soil. Considering from the actual arsenic concentration of pore water and extracted speciation from soils, high human health risk region of arsenic in soils become smaller than the environmental quality standard in this risk analysis.