本文报道了２７％皂素烟碱可溶性浓剂，在室内对菜青虫的拒食、毒力测定和田间小区药效试验结果。结果表明，本药剂对５龄菜青虫有较强的的拒食作用；对３龄菜青虫的ＬＣ５０为４２１９ｐｐｍ；在田间，以２０００倍液喷雾，施药后第２、７、１４天调查，对菜青虫的防治效果分别为９２２％、９７８％、９４８％；２５００倍液则为９４９％、９６０％和９１４％。施药后很快地得到保护叶片的效果，且在田间有较长的持效期。 In this paper, we report the antifeedant, virulence and field efficacy test results of 27% saponin soluble thickener indoors to Pieris rapae. The results showed that the agent had a strong antifeeding effect on Pieris rapae on the 5th instar; LC50 on the 3rd instar Pieris rapae was 4219ppm; in the field, it was sprayed at 2000 times and investigated on the 2nd, , Respectively. The control effects on Pieris rapae were 922%, 978% and 948% respectively, while those of 2500 times were 949%, 960% and 914%. The effect of leaf protection is quickly obtained after application and has a longer duration of action in the field.