A method for the determination of total flavonoids in Sophora japonica L. by coulometric titration was developed. The titration was carried out in a mixture of 1 mol/L KBr--2 mol/L HCl (1:1) and bromine was generated at the anode, rutin reacted with two moles of bromine with an n value of 4. The advantages of this method are simple and rapid, it can be used to analyze small amount of sample.