Abstract: Objective To study immunologic funtions of the spleen on patients with advanced gastric cancer (AGC) and to study immunologic funtions on patients by gastrectomy and splenectomy in plateau. Methods :The levels of T cell subgroups (CD3,CD4,CD8,CD4/CD8) circulatory immune complexes(CIC) and complenmentin(CH50,C3,C4) in 32 cases with AGC were measured in different part and stage Results(1) The cell levels of CD3,CD4,CD8,CD4/CD8 in peripheral blood lymphocytes(PBL) and spleen vein blood lymphocytes (SVL)and the levels of CH50,C3,C4 on patients with AGC were less than controls one's,but the levels of CIC were higher than controls (2) The levels of CD4,CD4/CD8 in PBL were less than ones in SVL on patients with AGC.(3) Whether by gastrectomy and splenectomy (R3) or only gastrectomy (R2) the levels of CD3, CD4, CD4/CD8 increase remarkly the levels of CD8 decrease but the levels of CIC decrease remarkbly on patients with AGC.(4) During short time (10-15 days) or long time(1-2 years) the levels of T cell subgroups were not different on patients by R3 or R2. Conclusion The immunologic functions of patients were decreased by advanced gastric cancer the functions of resisting cancer were increased also the immunologic functions were improved the immunologic funcitons wrer not injureed by gastrectomy and splenectomy.