Abstract: Simple cobalt tetraphenylporphyrins was synthesized and used to catalyze cyclohexene oxidation into cyclohexenone with air in the absence of additives and solvents.The cobalt metalloporphyrin was found to be very effective catalysts for the synthesis of cyclohexenone from cyclohexene.The research results showed that the temperature, air velocity,catalyst concentration and pressure influenced the yield and conversion of cyclohexene oxidation with air.For cyclohexene oxidation catalyzed by simple cobalt tetraphenylporphyrin, the conversion of cyclohexene was up to 21%, the yield of cyclohexenone reached 75%, under the optimum conditions of 0.4 MPa, 80 ℃ and 2.3×10^-5mol•L^-1 cobalt tetraphenylporphyrin.