The immunodepression model was established by means of intraperitoneal injection of cyclophosphamide in rats. Their phagocytic percentage and phagocytic index of peritoneal macrophages (PM phi) as well as serum lysozyme (LSZ) decreased obviously; After 6 days of acupuncture at "Zusanli" points (ST 36), PM phi phagocytic percentage and phagocytic index increased significantly, Serum LSZ showed no significant change. These results indicate that acupuncture can increase the phagocytic function of M phi in rats of immunodepression, but Serum LSZ level does not synchronously increase with the phagocytic function of M phi.