This study focused on the utilization of ozone to reduce endosulfan residues in Chinese cabbage. The experimental design used in the study was Randomized Block Design (RCB). 35% w/v EC of Endosulfanorganoclorine pesticide was used, with the recommended dose, to spray on Chinese cabbage every 7th day for three weeks. Five days after the last spay, the Chinese cabbage was harvested and ozone-dissolved water was used to reduce endosulfan residues in the cabbage at 5ºC at 5, 10, 15, 20, 25, 30, 35 and 40 minutes, respectively. The result showed that ozone-dissolved water at 25 minutes could effectively reduce 71.93% of endosulfan residues. This percentage was lower than the Maximum Residues Limit (MRL) of 2.0 mg/kg of vegetables proscribed by CODEX. Furthermore, the study found that the more time used, the less the purity of ozone-dissolved water. This resulted in the decrease of ozone efficiency to reduce endosulfan residues in Chinese cabbage.