Objective To investigate the relationship among Helicobacter pylori(H.pylori),CD4 positive cells and CD8 positive cells in gastric mucosa of the AIDS patients with gastritis.Methods Fiftyeight AIDS patients with upper abdominal pain were diagnosed with chronic gastritis through gastroscopy.The gastric biopsies from them were used for H.pylori detection with rapid urease test and Giemsa staining,pathology examination with HE staining,and immunohistochemistry analysis for CD4,CD8 positive cells in Gastric mucosa.And the application of flow cytometry was for the detection of peripheral blood CD4 and CD8 lymphocytes from the patients.Results H.pylori was positive in 26 cases,and negative was in 32 cases.CD8 cell expression in gastric mucosa of the AIDS patients with H.pylori positive was significantly higher than H.pylori negative patients(P＜0.05).There is no difference CD4 cell expression in gastric mucosa between the AIDS patients with H.pylori positive and H.pylori negative patients.Moreover,CD8 positive lymphocytes in gastric mucosa of those patients with H.pyloriinfection were significantly stronger than the CD4 positive lymphocytes.However,the peripheral blood CD4 lymphocytes from the patients with H.pylori infection were more than those from H.pylorinegative patients significantly(P＜0.05).Conclusion The expression level of CD8 cells in gastric mucosal tissues of AIDS patients with H.pylori infection were higher than those without H.pylori infection.The CD4 lymphocytes from the peripheral blood of the patients with H.pylori infection were more than those without H.pylori negative patients.