Abstract: Coulometric titration of daidzein with electrolytically generated bromine was studied.The titration was carried out in a mixture of 1'M KBr and glacial acetic acid(1: 1). An excess of bromine was generated, after standing for a certain time to let the reaction go to completion, a definite amount of arsenous salt was added and bromine was generated again to titrate arsenous salt to a dead stop end point.From the results, it is concluded that daidzein has reacted with four moles of bromine to give a value of 8, indicating that bromine has substituted all the hydrogen atoms at the positions ortho to the phenolic hydroxyl group.