To evaluate its safety, biological activity and immunogenicity of the recombinant H.pylori (Hp) adhesin conservation region(AB) in vitro so that to determine the feasibility of AB in Hp vaccination. ELISA assay was used to measure AB-specific antibody in serum of Hp infected patients. The proliferation of T cell in response to AB was examined by MTT test. Flow cytometry was used to evaluate the increase in FasL expression on T cells under the stimulation of Hp AB,T cell apoptosis induced by AB was detected by DAP assay.The effect of anti-AB serum on Hp binding of human gastric carcinoma cell lines was determined by light microscopy. Antibodies were detected in sera samples from 55 patients by ELISA, with RUT as parallel compare. Kappa value is 0.76. The low dose AB was capable of stimulating proliferation of T cells from Hp positive subjects. The effect of AB was significantly lower in both the induction of apoptosis and FasL expression of T cells than that of ATCC26695. Anti-AB serum could partially inhibit Hp binding to gastric epithelial cells. Under light microscopy, the adhesion of Hp to MGC-803 was significantly inhibited when pretreated the bacteria with anti-AB rabbit serum, compared with negative control which pretreated with pre-immunized rabbit serum. AB was a safe, immunogenicity thallus component, which can stimulate humoral and cellular immunity.Its antibody was capable of preventing the binding of Hp to gastric epithelial cell.