To observe the effect of Renshen Huangjing Decoction and Xiyangsen Decoction on strengthening yang and immunomodulatory effect of yang deficiency model animals. Methods:A total of 60 SD rats were surgical removal of bilateral testicles (castration) in rats. Animal model of kidney yang deficiency was established. Three days after surgery, the rats were randomly divided into a control group, a model group, a RH and XD decoction high-dose and low-dose groups, with 10 animals in each group. The effect of RH and XD decoction on penile erection latency in castrated rats were observed. Meanwhile, the organ coefficients of each group were compared. A total of 60 ICR mice were randomly divided into a control group, a model group, a RH and XD decoction high-dose and low-dose groups. Effects of RH and XD on spontaneous activity of kidney-yang deficiency, low temperature swimming on survival time and the change of body weight of mice were observed. The 60 ICR mice were randomly divided into a control group, a RH and XD high dose group and low dose group, and the drug was administered continuously for 16 days. Carbon clearance experiment was carried out in mice, to observe the effect of RH and XD decoction on the phagocytic clearance ability of reticulum endothelial system (RES) in mice, while the relevant organ coefficients were compared. Results:Compare with the model group, the high dose group of RH and XD Decoction can obviously shorten the erectile time of castrated rats penis (P<005), the weight coefficient of seminal vesicle and prostate were significantly increased by the quantity of reagent (P<005). The high-dose group can obviously improve the cold-tolerance and fatigue resistance ability of kidney-yang deficiency mice (P<005). RH and XD can significantly increase the viscera coefficient of carbon clearance mice (P<005). It has some effect on phagocytic index, but there was no statistical significance. Conclusion:RH and XD have obvious effect of tonifying kidney and strengthening yang and improving immunity