The present paper deals with preliminary study on the influence of clay mineyals and organic matter on specific surfacL area of colloids of some soils collected from northeast northwest. south and central China. The results obtained are summarized as follows: 1. A significant eorrelation between specific surface area of soil colloids and its clay mineralogical composition, the magnitude for specific surface area of the colloids of the soils was in the order: Black soil > Yellow brown earth > Loessal soil > Red earth > Latosol. The removal of free ion oxides from the latosol caused a considerable reduction in, specific surface area of its colloid while the removal of free iron oxide from the yellow brown earth resulted in the increase in specific surface of the soil.