The present paper deals with the frequency distribution of clay minerals in the soils of China. The soils in the arid and semiarid regions of northern China contain large amount of illite. South of the Hwai River, the content of illite is decreased markedly with the increase of rainfall. However, illite is still dominant in the soils derived from micaceous parent materials. Except the laterite and some terra-rossa, all soils including red and yellow earths contain more or less illite. Vermiculite and chlorite are always associated with mica and illite. In the soils of semiarid and subhumid regions, vermiculite is a common accessory mineral of illite. In the tropic and subtropic regions, vermiculite is usually associated with kaolin in the red and yellow earths, but not found in the laterites. Montmorillonite has been identified in the clays of chernozem and chestnut earth. Small amount of montmorillonite is also found in rendzinas, paddy soils and some young soils derived from recent effusive volcanic rocks.