The purpose of this research is to evaluate the areation treatment of both Feng-San reservoir and Cheng-Ching lake in reducing the odor problem and the growth of aquatic odor- producing microorganisms.For Feng-San reservoir,during the one year aeration treatment the lowest threshold odor number（TON）of 1.8 was in March while the highest TON of 8.0~8.5 was in August-September.
