Effect of storage temperature, washing, and cooking on postharvest-treated pesticide residues in polished rice was investigated. After being treated with each 500 mg/kg of captan, carbaryl, phenthoate, fenthion, fenitrothion, chlorpyriphos-methyl, pirimiphos-methyl, the polished rice was stored for 8 weeks at 4 and 3$0^{circ}C$, respectively. The penetation rate of carbaryl was the highest as 27.5% and the others, 13 to 18%. The half lives of pesticide residues were estimated as 30 to 230 weeks at 4$^{circ}C$, but 1 to 12 weeks at 3$0^{circ}C$. The residues were reduced faster at 3$0^{circ}C$ than at 4$^{circ}C$. The half lives of pesticide residues by water washing were estimated as 0.7 to 4.6 trials and the removed with the washing trials. The residues of captan and carbaryl in cooked rice were removed 100 and 98%, respectively, comparing to initial residues concentration in treated rice but those of other 5 pesticides were removed 80%.