A novel method to identify natural dyes used on silk cloth is presented by the measurement of their emission and excitation spectra. Vegetable dyes such as safflower, sappan wood, madder, and a combination of Chinese tannin and cochineal each with different kinds of mordant were tested. Each dye was found to show a characteristic pattern in emission and excitation spectra with little change before and after fading; thus this method is useful in the identification of dyes. -- AATA