In order to investigate the relationship between gastric juice ammonia concentrations and severity of inflammation in helicobacter pylori (Hp ) associated gastritis. Gastric juice ammonia concen- trations were measured in 39 cases Hp -positive and 23 cases Hp -negative chronic gastritis patients .at the same time , the severity of inflammation in gastric untral mucosa was also evaluataed by the method of polymorphonuclear (PMN) and mononuclear (MN ) count. The results showed : gastric juice ammonia concentration in Hp -- positive gastritis group (84.10?33. 07mg/L)was significantly higher than that in the negative group (22. 59?13. 12mg/L) (P