Dyeing properties of the colorants extracted from pomegranate hull on silk fabric were investigated. Pomegranate colorants were characterized by FT-IR analysis. Effects of dyeing condition and mordanting on dye uptake, color change and colorfastness were explored. Pomegranate colorants showed high affinity to silk fiber and its isotherm adsorption curve was Langmuir type. Therefore, ionic bond was involved in the adsorption of pomegranate colorants on to silk fiber. Mordants except Fe did not significantly increase dye adsorption. Pomegranate colorants produced mainly yellow color on silk fabric, but the silk mordanted with Fe showed yellow red color. Fastness to washing, perspiration, and rubbing was not improved by mordanting treatment, but light colorfastness was increased by Fe mordant.