To study the effect of injection position on the clearance in mice, ink was injected into the mice from vena plexus in inner cathus and vena in tail separately, and the clearance index were detected. The results presents no statistical difference. The phagocytic index was detected immediately after sampling and 24 hours after sampling, and the results presents no statistical difference too. It was concluded that there is no differene between the methods of the two tests and they have closely correlation. Author's address Health and Anti-epidemic Station of Beijing, Beijing PRC,100013 PRC.