Researches to preserve and restore the remaining fabrics as costume heritages have been carried out. In this study, in order to artificially restore an excavated silk fabrics, degummed silk fabrics and safflower dyed silk fabrics were prepared for an experiment. These fabrics were photo-degraded by the Xenon arc beam to have various strength retention(100%, 80%, 60%, 40%, 20%). The fine structure and physical properties of Xenon arc treated fabrics were investigated with various techniques such as tensile test, weight loss, wide-angle X-ray diffraction, yellowness, color, SEM etc. Tensile strength and the crystal diffraction intensity of silk fabrics decreased as Xenon arc beam treatment time increased. Weight loss increased slightly. Strength retention was decreased as the Xenon arc beam treatment time goes by. (Yellowness of the undyed silk fabrics and L* of the dyed silk fabrics increased. Whiteness of the undyed silk fabrics and b* of the dyed silk fabrics decreased.) SEM results of the silk fabrics treated Xenon arc beam show that surface was a little damaged.