In this study, by using oleic acid and polypropylene glycol, good natured antifoaming agent for suitable electronics process under the alkaline conditions were synthesized. For the synthesized mono and diesters, acid value, hydroxyl value was measured, and identified by FT-IR and 1H-NMR spectroscopy. Surface properties such as surface tension, critical micelle concentration(cmc) for diluted aqueous solution was measured, and tested the antifoaming properties according to the difference of alkyl chain length, various concentration, temperature and pH. The surface tension of synthesized antifoaming agent, PPMO(Polypropylene glycol monooleate) was 24.3 dyne/cm, PPDO(Polypropylene glycol dioleate) was 23.7 dyne/cm. By increasing of the alkyl chain length, surface tension was decreased slightly, and showed good antifoaming properties at 0.06 wt% concentration and 50℃, pH 11. These synthesized compounds are expected to apply as a suitable antifoaming agents in the semiconductor and the PCB(Printed Circuit Board) manufacturing process.