Effect of air pollution on dyed stuff and some fibers was examined by exposure to air for three months. The exposure was made on 22 points in the Yamashina area in Kyoto city, from January to March, 1969. Acetate rayon cloth dyed with Diacelliton Fast Brilliant Blue B, knitting wool dyed with Orange I, and filter papers dyed with several kinds of indicator, and silk, acryl, polyester, cupra and nylon fibers were examined. During this examination period, concentration of sulfur oxides and nitrogen dioxide in air was measured by the alkaline filter paper method once a month. Change in the color of dyed acetate rayon cloth was found to be correlated to the concentration of nitrogen dioxide, and that of dyed knitting wool to the concentration of sulfur oxides. Filter paper dyed with indicators showed visually the concentration of polluting gas in the atmosphere. Acryl and polyester fibers did not show any change by exposure to polluted air but the remaining three kinds of fibers were found to become fragile in the order of cupra, silk, and nylon. Fragility of cupra was found to be correlated to the concentration of polluting gas in the atmosphere.