Chronic gastritis (CG) is an inflammatory condition of the gastric mucosa,induced by various causes.A commonly-seen disease in clinical practice,it is found in about 80％-90％ of patients undergoing gastroscopic examination.The prevalence rate in the general population remains unclear.It is generally considered that its incidence rate accords with Helicobacter.pylori infection rate and the prevalence of CG is 30％-80％ in China.Possible etiological factors include H.pylori infection,smoking,drinking alcohol,food allergies,duodenal juice reflux,drug-induced injuries,heredity,immunity,and radiation.