The action and efficacy of Ornidazole are mainly as follows: I. Treatment of protozoal infections, trichomonas infections, amoebic protozoal infections (intestinal and hepatic amoebiasis, amoebic dysentery, amoebic abscess). II. Treatment of anaerobic bacterial infections, such as septic meningitis, peritonitis, post-operative wound infection, postpartum sepsis, septic abortion, endometritis and other infections caused by sensitive bacteria, and prevention of anaerobic bacterial infections after various surgeries. The main usage and dosage are: in the treatment of anaerobic bacterial infections, 500mg/d twice daily for adults; 10mg/kg for 12 hours for children. in the treatment of amebiasis, 500mg twice daily for adults and 25mg/kg/d for children. in the treatment of trichomoniasis, 1-1.5g once daily for adults and 25mg/kg/d for children.