Abstract: In order to investigate the absorption, distribution, metabolism and excretionmechanism of the biphenyl diester and to determine its concentration in patient'sblood for rational clinic dose dimethyl-3, 3'-dibromo-4, 4'-dimethoxy-5, 6, 5'6'-bismethylene-dioxy-2,2'-dicarboxylate was synthesized. ~3H-biphenyl diester ofhigh specific radioactivity was prepared by highvoltage-discharge catalytictritium-bromine exchange method and purified with TLC. Specific activity is 182.4GBq/mmol (4.93 Ci/mmol). Its stability was tested.