Abstract: Samples were collected of soils from the plow layers of the major Chinese medicinal herbs production areas in Jinhua and of the Chinese medicinal herbs produced therein for analysis of heavy metal contents and causes of their overproof rates from the environmental geochemical aspect. Results show that the Cd overproof rate in Rhizoma Atractylodis, Macrocephalae,Radix Scrophulariae and Bulbus Fritillariae Thunbergii is 64.3%, 40.0% and 47.2%, respectively, and the Cu overproof rate in Rhizoma Atractylodis, Macrocephalae,Radix Scrophulariae and Bulbus Fritillariae Thunbergii is 35.7% ,10.0% and 5.9%, respectively. It was found through studies on the characteristics of Chinese medicinal herbs selectively absorbing certain heavy metal elements, soil environment of the herb growing areas, topographic and climatic conditions that the warm humid climate, steep terrain, strong eluviation in the process of pedogenesis through weathering of rocks, decreasing pH from soil parent material, eluvial horizon to plough layer and soil acidification are the major causes leading to overproof Cu and Cd in the Chinese medicinal herbs.

Key words: Chinese medicinal herbs, soil, heavy metal, environmental geochemistry, Jinhua