Immunoregulative action of 70% ethyl alcohol fraction of Cervus nippon was investigated in vitro. The fraction enhanced the proliferation of thymocytes and the population of CD4$^$+/CD8$^$-/ single-positive cells in thymocytes. CN-E enhanced [Ca$^$2+]$sub$i/, the production of TNF-${alpha}$ and IL-1 ${eta}$, and phagocytosis in peritoneal macrophages. The fraction did not induce the proliferation of splenocytes and DNA fragmentation in thymocytes. These results indicate that 70% ethyl alcohol fraction of Cervus nippon regulates immunological action by stimulating murine thymocytes and macrophages.