Abstract: Fourier-transform infrared(FT-IR) spectrometry was applied to the discrimination of 4 kinds of natural leathers,i.e.pig leather,cattle hide,sheep leather and horse hide,by collecting their IR spectra with the OMNI sampler and pretreating the initially obtained IR spectra to extract their characteristic informations.A 2-dimensional distribution diagram was prepared by using the origin 7.0 chemical sotware,taking the ratios of peak areas at 2 925 cm-1 and 2 854 cm-1 as abscissa,and the ratios of peak areas at 1 652 cm-1 and 1 552 cm-1 as ordinate.It was shown in the diagram that the distribution of sample points of the leathers of pig,cattle and horse are centralized better than the distribution of sample points of sheep leather;and that pig leather can be clearly discriminated from leathers of cattle,sheep and horse while horse hide can be clearly discriminated from leathers of cattle,sheep and pig.There is a small area where sample points of leathers of cattle and sheep overlapped each other.