Abstract: The mineral substances and humic acids of three typical soils (red soil, fluvo-aquic soil and black soil) and their adsorption with herbicide butachlor were studied using Fourier transform infrared spectroscopy (FTIR).The results showed that the inorganic components of red soil from Jiangxi are mainly kaolinites, which rise absorption bands at 3 703, 3 628, 1 089, 1 035, 914, 696 and 471 cm~ -1, and that of fluvo-aquic soil from Beijing and black soil from Heilongjiang are mainly montmorillonites, which appear peaks at 1 432 and 872 cm~ -1. It also can be concluded that humic acids from different soils contain the same classifical functional groups, i.e. alkyl, aromatic hydrocarbons, carbonyl, ethanol, phenol and acid, etc. The mechanism of adsorption of butachlor on humic acids is the formation of H-bounds on carbonyl.