Abstract: The physicochemical properties of Bi-P catalyst system and the mechanism of oxi-dation-dehydrodimerization and aromatization of propylene were investigated by using XPS,PAS, TPR and X-ray diffraction methods.The results indicated that propylene is dissociatively adsorbed on the surface of the catalyst and the activation of α-hydrogen is related to the strength of metal-oxygen bond in the catalyst. The products of ally loxidation depend on the electron transference between the allylic intermediates and the catalyst.