Abstract: Biochemical nematicide Weixianke was applied to control sweet potato stem nematode in Qinhuangdao, Hebei Province.The results showed that the average decrement of population of Ditylenchus distructor was 89.44%, average control efficiency on D.distructor was 76.08%, the yield of sweet potato increased 607.25%.The studies indicated that Weixianke possesses the prospect in controlling nematode instead of chemical nematicide.