All the surface activities including surface tension, foaming power, foam stability, emulsifying power, dispersion effect, and detergency were measured and critical micelle concentration(cmc) was evaluated in dilute aqueous solution. The cmc evaluated by the Ring method was 10^-3∼10^-4mol/L in case of monoesters, and 10^-3∼5.0×10^-5mol/L in case of diesters, respectively. Surface tension of the aqueous solution was decreased to 45∼50dyne/㎝, showing the tendency that the ability of lowering the surface tension was dependent on increasing of carbon atom number in alkyl chain. Foaming power of all the monoesters was better than that of diesters. while foam stability of diesters was to the contrary. Emulsifying power of soybean oil or benzene was specially expected to be good for emulsifiers in industrial application fields. HLB values of monoesters and diesters evaluated by Griffin`s method were in the range of 8 to 12. Dispersion property of ferric oxide was stable in the range of 4.5×10^-5∼5.0×10^-4mol/L in case of monoesters, and 10^-5∼10^-4mol/L in case of diesters.