his report presente the studies on the effect of Bifidobacteria on the phagocytic fuction ofmononuclear phagocytes and the proliferation of lymphocytes in mice. The phagocytic function ofmononuclear phagocytes was tested by the carbon clearance test

which showed that Bifidobacteriacould accelerate the phagocytic activation in mice treated inrtaperitoneally. The lymphocytetransformation test showed that Bifidobacteria could directly induce proliferation response ofspleen lymphocytes and aynergetically with conA to promote DNA synthesis of mouse splenocytesin vitro.