The surface modification of the silk fiber was carried out with the aim to increase the weight loss and to improve its physical properties. The graft-copolymerization with ascorbic acid and hydrogen peroxide as the initiator system was investigated using methylmethacrylate (MMA) and acrylonitrile (AN) monomers under the influence of microwave radiations. The percent graft yield had a significant effect on various reaction parameters which include reaction time, temperature, monomer and initiator concentrations.The maximum graft yield was found to be 100.4% and 8.9% with MMA and AN monomers, respectively.The grafted fibers were characterized by various techniques such as infrared spectroscopy (FT-IR), scanning electron microscopy (SEM)and Thermogravimetric analysis (TGA).