Abstract: The relation between the oxygen absorption and the composition of oxidized wax in the course of liquid-phase deep oxidation of paraffin wax has been studied. The experimental results show that the oxidized wax is almost composed of acids with different functional groups, of which carboxyl group predominates, ester group is the next (about one half the quantity of carboxyl), then comes the carbonyl group, but the hydroxyl group is almost zero. When the acid value of oxidized wax amounts to about 250mg.KOH/g., an appreciable amount of C4-C10 dibasic acids commencos to be produced, and their yield will be rapidly increased as the oxidation proceeds more deeply. With a suitable catalyst and better contact between the gas and the liquid, the rate and selectivity of the deep oxidation reaction of paraffin wax are dependent on the reaction temperature and the partial pressure of oxygen used, so that the oxidation should be carried out as much as possible under chemical kinetic conditions to reduce the effect of diffusion. Furthermore, the experimental results show that the ratio between the ester value and acid value may be considered as an index to show whether the diffusion rate of oxygen meets the requirements of the kinetic velocity of oxidation or not. This ratio may also be used to estimate the maximum acid value that oxidation can produce. The variation of the product yields in the oxidation reaction indicates the rapid decrease of oxidized wax in the final reaction stage due to the very high velocity of formation of CO2 and condensed water phase. When acid value exceeds 400, the yield of C4-C10 dibasic acids up to 40% will result. By chromatographic analysis, it is found that the yield of succinic acid in general is the highest, glutaric acid the next and that of C4-C5 and C6-C10 dibasic acids in about equal quantities.