Air foam flooding was one of the effective EOR methods. In order to research the mechanism of low temperature oxidation by air injection process, this study was carried into execution. Its main contents included air and formation oil phase behaviors, reaction kinetics of low-temperature oxidation, influencing factors of low temperature oxidation and the reaction path and reaction domain of low temperature oxidation. The results showed that the single degassing volume shrinkage of Huzhuang oil was 10.1126%, and the saturation pressure was 6.36 MPa at 90℃. The volume of oil increased 5.49% when the temperature increased from 90℃ to 150℃ and the pressure was 23.5 MPa. 9.07% air of its own volume could solve in oil and swelling factor was 3.68% at the formation condition (90℃、23 MPa). The reaction of low temperature oxidation between formation oil and air was first order reaction with 5.1×10^-3 h^-1 reaction rate constant, 81.9 kJ/mol activation energy, and 2.85×10⁹ h^-1 pre-exponential factor. The value of activation energy was high, but the activity was lower. Huzhuang oil was provided with the higher consume ability of oxygen. In 96 days, the oil consumed 2.4 times its own volume of oxygen in the air, and the oxygen volume fraction separated from oil was less than 3%. Increasing temperature or pressure, adding clay or formation water could enhance the reaction rate. Temperature was the main factor. Oil oxidation characters depended on its group composition. After the low-temperature oxidation reaction, the relative amounts of saturated and aromatic hydrocarbons reduced, and that of resin, asphaltene and oxygen increased. Formation oil oxidation reaction at low temperature could be divided into two steps, adding oxygen reaction and chain breaking reaction.