Abstract: The therapeutic efficacy of mebendazole and pyquiton against Trichinella spiralis of different stages in 146 mice was studied. Oral administration of mebendazole 50mg/kg×1d on excysted larvae and adults, resulted in 100% and 82.8% of reduction rate respectively; 50mg/kg×7d significantly reduced the number of invasive larvae and encysted larvae by 92.7% and 99.6% from muscle as compared with the controls. The results indicated that mebendazole was effective against both intestinal and muscular phases of T. spiralis. No effect was observed with pyquiton in doses of 600mg/kg×1d against excysted larvae and adults, and 300mg/kg×3d (o.a.) or 100mg/kg×3d (i.m.) against invasive larvae and encysted larvae.