1. Objectives The purpose of this study is to investigate the anti-oxidative and immune regulatory effect of oral administration of Chungsimyeonja-tang decoction in aged rats. 2. Methods The rats in the normal group were 14 weeks old, and those in the control and Chungsimyeonja-tang groups were 40 weeks old. The rats in Chungsimyeonja-tang group were orally treated with chungsimyeonjatang decoction daily for 2 months. To observe the anti-oxidative effect and immune regulatory effect of Chungsimyeonja-tang, we performed blood chemistry analysis, histological analysis. 3. Results and Conclusions 1) The number of WBC in blood was significantly increased and the number of PLT in blood was significantly decreased by oral administration of Chungsimyeonja-tang decoction. 2) The levels of albumin, LDL cholesterol, ALP and GOT in serum were significantly decreased, and the level of glucose in serum was significantly increased by oral administration of Chungsimyeonja-tang decoction. 3) The concentrations of glutathione and catalase were significantly increased and the concentrations of NO and MDA were significantly decreased in the liver of early aged rats by oral administration of Chungsimyeonja-tang decoction. 4) The concentrations of SOD and catalase were significantly increased and the concentration of MDA was significantly decreased in the lung of aged rats by oral administration of Chungsimyeonja-tang decoction. 5) The levels of IL-4 and IL-6 were significantly decreased while the levels of IFN-${gamma}$ were significantly increased in the spleen of early aged rats by oral administration of Chungsimyeonja-tang decoction.