Polymer-supported 4-(2-pyridylazo) rosorcinol-metal complexes (PS-PAR-M, M = Cu, Co, Ni, Fe) were prepared and characterized by IR, ICP, XPS, and used in the oxidation of ethylbenzene as catalyst. In comparison with their catalytic activities, PS-PAR-Cu was a more effective catalyst for the oxidation of ethylbenzene without solvent. The influences of reaction temperature, the amount of catalyst and substrate concentration, as well as reaction time on the oxidation of ethylbenzene have been investigated. The reaction optimum conditions have been obtained.