Abstract: The seletctive toxicity of 14 insecticides between Spodoptera litura and Bombyx mori was investigated by leaf dipping method in the laboratory. The results showed that the toxicity order of 14 insecticides to Spodoptera litura was arranged as follows: Indoxacarb > emamectin benzoate > chlorfenapyr > methoxyfenozide > spinosad > deltamethrin > lambda-cyhalothrin > fipronil > chlorpyrifos > tebufenozide > abamectin > profenofos > beta-cypermethrin > methomyl. The toxicity order to Bombyx mori was arranged as follows: emamectin benzoate = abamectin > deltamethrin > spinosad > beta-cypermethrin >indoxacarb > lambda-cyhalothrin > chlorpyrifos > tebufenozide > methomyl > fipronil > profenofos > methoxyfenozide > chlorfenapyr. The seletctive toxicity of chlorfenapyr was the highest among 14 insecticides tested, and its seletctive toxicity ratio（STR, Bombyx mori LC50 / Spodoptera litura LC50）reached 36.26. Indoxacarb showed rather high seletctive toxicity, and STR was 5.56 . The seletctive toxicity of abametin was the lowest. The results suggest that chlorfenapyr is an insecticide suitable to control Spodoptera litura in mulberry field and safe to Bombyx mori.