To investigate the significance of anti helicobacter pylori (Hp) therapy to the patients of cirrhosis company with Hp infection, sixty three cases of patients were divided into two growps randomly, control group (CG) and treated group (TG) .The patients in TG were treated with oral omeprazole, Clanithromycin and Motronidazole by oral administration, while Oral omeprazole was only given to the patients in CG.Before and after treatment of two and four weeks, the data in both groups were analysed.Results:compared with CG, the concentration of ammonia in the patients of TG was decreased significantly (P<0.01) ;but it was increased significantly in CG after treatment (P<0.01) .The Anti Hp therapy is very important to decrease the serum ammonia and prevent the development of hepatlc encephalopathy.Strong antiacid could keep the pH in the stomach more than 6 for a long time, that the ammonia produced by urea enzyme will diffuse much into the blood and the serum ammonia will be increasing.It is suggested that the anti Hp therapy clinically is very important for the patients of cirrhosis company with Hp infection and we should pay much attention to that the ammonia will be increasing if the strong antacid are only used to the patients for a long time.