Effect of solvents, namely acetic acid, acetonitrile and ionic liquids （IL）, on oxidation of cyclohexane was investigated and iron porphyrin was used as catalyst. All solvents mentioned above improves conversions of cyclohexane, among which IL is the best, followed by acetonitrile and then acetic acid. Conversion of cyclohexane increases along with acidity of IL. Under conditions of 145 ℃,O2 pressare 0.8 MPa, 3 h, 5 mg catalyst in 25 mL of N-butylsulfonic acid pyridinium hydrogen sulfate, conversion of cyclohexane is 20. 8%, and selectivity to KA oil （cyclohexanol and cyclohexanone） is 82.6%. The products can be separated with IL by decantation. The IL can be reused for three times after removal of water under vacuum.