Abstract: “Minong 9 "hami melon as test materials, Hami melon were bagged with white permeability film bags, woven bags, common polyethylene food bags respectively after pollination 17 days, CK was not bagged. The effect of quality of postharvest Hami melon with preharvest bag processing was studied. The result showed that the rate of decline of firmness, VC, titratable acid and soluble solids content were restrained by white permeability film bags treatment. The synthesis of flavonoid was restrained in the growth process by common polyethylene food bags treatment. The increase of weight loss rate was suppressed effectively by woven bags treatment. The effect of fruit shapes index was not affected obviously by the three bags treatment.