Abstract: A simple, rapid and accurate method for the quantitative determination of fluorescent brightener OB, 2, 5-bis-(5-t-butylbenzoxazolyl)-thiophene, by HPLC is described. An YWG C18 colum was used and an eluent of 67% tetrahydrofuran-wter at a flow rate of 1.0mL/min was seleced. The separation was performed in less ha 11min at 40℃ and detected at UV 360nm. The method has been used to test industrial sample with satisfactory results.