Abstract: NIH mice infected with Schistosoma japonicum cercariae for 3,7, 14,21 or 35 d were treated ig either with arteether or artemether at the daily dose of 100～200 mg·kg^-1 for 2 d , the efficacy produced by both drugs was similar. The d 7schistosomules and d 35 adult worms were more susceptible to arteether or artemether withrespective worm reduction rates of 77.5% ～87.2% and 51.7% ～61.3%. Histologicaland histochemical studies showed that d 7 and d 35 schistosomes, harbored in micetreated with arteether 300 mg ·kg^-1 ·d^-1 for 2 d appeared in cloudy swelling andvesiculation in the tegument, distension of intestine, apparent decrease or even disappear-ance of glycogen and inhibition of alkaline phosphatase activity in the tegument andparenchymal tissues, as well as formation of dead worm granuloma.