The fiber composition label in accordance with the Household Goods Quality Labeling law is determined by identification and quantitative analysis of fiber mixtures in JIS L 1030-1,-2 (Japan Industrial Standards). But, this method involves destructive inspection, and a lot of time is necessary for the analysis. In this study, using textile products of cotton and polyester, we examined the ... [Show full abstract] possibility of qualitative and quantitative analysis of fiber composition by infrared spectroscopy and SIMCA (soft independent modeling of class analogy) and PLS (partial least squares regression). By using SIMCA, we tried to classify the infrared absorption spectrum of textile products to composition fiber. And by using PLS regression, the fiber composition could be forecast from the infrared absorption spectrum of textile products. The technique that we propose is nondestructive and quick.