Epoxidized cotton seed oil (ECSO) was conveniently synthesized from cotton seed oil (CSO) in the presence of hydrogen peroxide, formic acid, and phosphoric acid. Then the ECSO was converted into carbonated cotton seed oil (CCSO) by reacting with CO2 using tetrabutylammonium bromide as a catalyst. The reaction conditions including reaction temperature, pressure, reaction time and the amount of catalyst were examined. In addition, the final product (CCSO) from cyclic addition reaction was characterized by FT-IR, 1H NMR and TGA. Compared with CSO and ECSO, CCSO showed excellent thermal and oxidation stability. Additionally, the CCSO's properties of extreme pressure, anti-wear and friction reduction were tested and analyzed. The results indicated that it could be used as potential lubricating base oil.