Abstract: The amoebicidal activity of a range of concentrations of tinidazole (fasigyn) synthesized by the Institute of Parasitic Diseases, Chinese APM was determined on the in vitro cultures of Entamoeba histolytica (T and B strains) in a diphasic LAS medium.The results indicated that after 72 hours' incubation tinidazole was 100% lethal at 512μg/ml, at which both T and B strains of E. histolytica trophozoites were killed. At the concentration of 64-256μg/ml, the growth of trophozoites was inhibited to a certain extent. The results obtained compared well with those obtained with metronidazole. It is suggested that tinidazole might be used for clinical trial.