The purpose of this study was to investigate the effects of Kami boatang(KBT) on the immune cells in Balb/c mice. KBT (500mg/kg) was administerd p.o. once a day for 7 days. KBT enhanced the proliferation of thymocytes and splenocytes. KBT enhanced the subpopulation of helper T(Th) cells, but did not affect the subpopulation of Thyl/B220 cells and Th/Tc cells in splenocytes. KBT enhanced the production of ${gamma}$-interferon and interleukin-2 in thymocytes, but decreased the production of interleukin-4. KBT enhanced the production of ${gamma}$-interferon, interleukin-2 and interleukin-4 in splenocytes and serum. KBT suppressed the production of nitric oxide, and enhanced the phagocytic activity in peritoneal macrophages. These results suggest that KBT has a potent activity on the immune response via the increase of the production of cytokines and phagocytic activity in vivo.