The purpose of this research was to investigate effects of mixed extract of Ginseng Radix and Angelicae gigantis Radix on activity of murine splenocytes and macrophages. GAE (300 mg/kg) was administered p.o. for 7 days. GAE decreased the viability of murine splenocytes in vivo. Also, GAE enhanced the population of $Thy1^+$ cells in splenocytes and the population of splenic $CD4^+$ cells. Furthermore, GAE increased the production of ${Upsilon}$-interferon from splenocytes. GAE enhanced the production of nitric oxide and the phagocytic activity of peritoneal macrophages. These results suggest that GAE regulates the immune response via activation of splenic Th1 cells and peritoneal macrophages.