Abstract: Coulometric titration of diosgenin with electrolytically generated bromine was studied.Diosgenin has a double bond at the 5～6 position so it can add one mole of bromine. The reaction takes place easily and is quite straightforward.The titration was carried out in a mixture of 1 M KBr-18%HC1 and 95% EtOH (1:1), and bromine was gerenated at the anode. The end point was deteced by the deadstop method.This method is simple, rapid and precise and is suitable for determining small amount of diosgenin.