Abstract: Cerium ammonium nitrate (CAN) is an expensive and powerful selective oxidant. It has played an important role in organic synthesis. Because it is a single electron oxidant,many organic reactions need large quantities of it. The application of CAN in organic synthesis in the oxidation of alkyl aromatics has so far been limited. In this paper, we wish to report a new method of oxidation of active α-H of aromatic hydrocarbon by CAN/NaBrO₃/H₂O system. Only catalytic amount of CAN was needed in this method and the selectivity was improved as well.