The field trial was conduced on chlorpyrifos 30% EW, synergistic mixture of chlorpyrifos 30% EW with additive, chlorpyrifos·chlorfluazuron 10% EW, chlorpyrifos 40% EC against Chaphalocrocis medina Guenee was carried out. The results showed chlorpyrifos 30% EW and chlorpyrifos 40% EC have the similar control effect, chlorpyrifos·chlorfluazuron 10% EW has the highest control effect at last. When be adding additive, control effect of synergistic mixture of chlorpyrifos 30% EW with additive was batter than that of chlorpyrifos 30% EW, but it take effect was latter than chlorpyrifos 30% EW.