Abstract: A new antioxidant dithiodinglycol distearictate was synthesized starting from thiodiglycol and stearic acid using p-toluenesulfonic acid as catalyst and xylene as water carrier. Optimized reaction conditions were obtained through orthogonal test as：reaction temperature of 160－170 ℃，mass ratio of catalyst to reactants of 1.0%，molar ratio of alcohol to acid of 2∶1 and the water entraine xylene of 15mL. Under these conditions，the yield of dithiodinglycol distearictate was up to 94.2%. The product was identified by IR and MS，and its antioxidation properties used in polypropylene resin were studied. The antioxidant was proved to present excellent performance by the tests of melt flow rate (MFR)，tensile strength and elongation when used in PP.