The supported Nb/USY catalyst with molecular sieve USY as support and niobium acid as Nb source was synthesized by the method of impregnation. The samples were characterized by means of XRD, FT-IR TG-DTA. Using H2O2 as oxidant and Thiophene of isooctane solution as the simulated oil to do experiment. The effects of Nb-Ioading, caIcination temperature and time on the cataIyst activity and the performance of the catalyst regeneration were studied. Through analyzing of the oxidation product, explore the mechanism of oxidative desulfurization. The experimental results indicated that,when the amount of niobic acid loading is 15%, caIcination temperature is 300℃, time is 120min, Nb/USY exhibited the highest activity,in addtion, its regeneration properties were good, the final oxidation product of Thiophene is sulfate.