Abstract: Based on the characteristics absorption of Infrared spectra and the Intensity differences of absorption for OH groups in high frequency range, qualitative and quantitative analysis for clay minerals of kaollnites were made. It is thought the method of Infrared absorption spectra is more time-saving and more accurate, as comparing with X-ray diffraction. Furthermore, the interference from chlorite can be eliminated. It is particularly appliable to the samples of low content (10%minor).