Abstract: Objective In order to study the killing mechanism of albendazole on Hymenolepis nana and its eggs.Methods The killing effect of albendazole of different concentration on Hymenolepis nana in vitro was observed and compared by morphological methods.Results The worm virality was obviously reduced at 48 hours in all test groups.The worms in high concentration groups were all dead at 72 hours.The worm's body surface was damaged more seriously with the drug concentration increasing and the test time extending.The tissue structure impaired obviously.The nuclei in every parts were seen the phenomena of pyknosis and karyorr hexis eggs' form was changed and the amount of eggs was reduced evidently at 48 hours.Conclusions The results indicated that albendazole damaged Hymenolepis nana and its eggs strongly.