Abstract: Discharge printing of the real silk fabric was performed with vat dye paste for printing the patterns and vinyl-sulfone reactive dye for the ground. The effect of vat dyes,reducing agents and alkali dosage on printing was analyzed.The color fastness and the strength of the printed silk fabric were tested with the purpose of investigating the possibility of this application.The result indicates that the application of vat dye paste to the discharge printing of real silk fabrics can obtain brilliant shade and good color fastness,but lower the strength of the fabrics.