Abstract Objective: To estimate directly phagocytic functions of the macrophages because of the importance in innate immunity, determine blood vessel density and re-innervation density which are basis of function. Methods: Eighty adult Wistar rats were randomly divided into experimental and control groups. The formers underwent splenotomy and a half splenic slice was transplanted into greater omentum. The latter only moved. After 6 months, examination was made as follows: ① After injection of 0.4% carbon particles by vein, splenic tissues were taken out at different times for estimating phagocytosis by light microscope. ② When splenic tissues had been intubated into left ventricle under total anesthesia, animals were perfused by formalin and India ink mixture suspension. Splenic tissues were taken out for making sections for measurement of area density of blood vessels. ③ Immunohistochemical procedure was used for detecting neuropeptide Y (NPY). Results: Phagocytic functions had no difference between two groups, but the area density of blood vessels and NPY-positive fibers redued ( P ＜ 0.01 ) in experimental group. Conclusion: Autotransplanted splenic tissues show good innate immunity though regeneration of blood vessels and nerves do not reach normal level.