The catalytic activity of ten lipases from different sources was compared for the esterification of oleic acid and oleic alcohol to produce oleyl oleate, a new kind of additives used in cosmetic. The whole-cell lipase of Rhizopus chinensis CCTCC M201021 showed the highest conversion (above 90%). Various reaction parameters were optimized to obtain high yield of oleyl oleate. The optimum concentration of oleic acid was 0.3 mol/L, the best organic solvent was n-hexane, and the suitable water content of the dr...