[Objective] To inspect the influence of Veratrum Nigrum on the body resistance strengthening function of Panax Ginseng with different proportion and dosages. [Methods] ICR mice were divided,according to their weights,into normal group,model group and Panax Ginseng group of different dosagess. Immunocompromised mouse were constructed by intraperitoneal injection with cyclophosphamide(45 mg/kg,qod × 3). Medicines were administrated since the first day of modeling,once per day for 7 days in total,so as to find out the effective dose range of Panax Ginseng. With uniform design and medicine administration with 2 factors 11 levels,observing the influences of different proportions and dosages of combined decoctions of Panax Ginseng and Veratrum Nigrum through the index of immune organs(spleen and thymus),ability of carbon clearance and blood routine of the modeling mice. [Results]Comparing with the mice in nnormal group,ones in modeling group had obvious reduction in the body mass,visceral index,phagocytic function and blood routine. Splenic index,phagocytic correction index,WBC,RBC and Hb increased significantly with only using Panax Ginseng(0. 5- 8. 0 g /kg). Evaluation of the influence of Veratrum Nigrum on the body resistance strengthening function of Panax Ginseng based on uniform design:(1) Influence on the index of immune organs:Decoctions(Veratrum Nigrum + Panax Ginseng 0. 53- 8. 05 g /kg) had no obvious effect on the index of immune organs of immunocompromised mice.(2) Influence on the ability of carbon clearance: Veratrum Nigrum could reduce the ability of Ginseng to enhance the phagocytic function(Panax Ginseng∶ Veratrum Nigrum < 100 ∶1) in direct proportion. The strongest antagonistic effect of Veratrum Nigrum would be achieved when the total dose of decoctions was 3. 08 g/kg(Panax Ginseng∶Veratrum Nigrum =9∶1).(3) Influence on blood routine: if Panax Ginseng∶Veratrum Nigrum <100∶1,the effect of Ginseng to increase WBC and RBC would be counteracted by Veratrum Nigrum(0. 034-0. 13 g/kg)without influencing the dose-effect curve of Ginseng. The strongest antagonistic effect of Veratrum Nigrum would be achieved when the total dose of decoctions was 4. 58 and 3. 48 g /kg(Panax Ginseng∶ Veratrum Nigrum = 9∶1). The effect of Ginseng to increase Hb would also be counteracted by Veratrum Nigrum but the dose-effect curve of Panax Ginseng would decline. [Conclusions]Within the dose range stipulated in the Pharmacopoeia,the body resistance strengthening function of Panax Ginseng may be reduced or counteracted by Veratrum Nigrum,and the intensity of effect changed with the imparity of proportions and dosages. [Objective] To inspect the influence of Veratrum Nigrum on the body resistance strengthening function of Panax Ginseng with different proportions and dosages. [Methods] ICR mice were divided, according to their weights, into normal group, model group and Panax Ginseng group of different dosagess. Immunocompromised mouse were constructed by intraperitoneal injection with cyclophosphamide (45 mg / kg, qod × 3). Medicines were administrated since the first day of modeling, once per day for 7 days in total, so as to find out the effective dose range of Panax Ginseng. With uniform design and medicine administration with 2 factors 11 levels, observing the influences of different proportions and dosages of combined decoctions of Panax Ginseng and Veratrum Nigrum through the index of immune organs (spleen and thymus), ability of carbon clearance and blood routine of the modeling mice. [Results] Comparing with the mice in nnormal group, ones in modeling group had obvious reduction in the body mass, visceral i ndex, phagocytic function and blood routine. Splenic index, phagocytic correction index, WBC, RBC and Hb increased significantly with only using Panax Ginseng (0.5-8.0 g / kg). Evaluation of the influence of Veratrum Nigrum on the body resistance strengthening function of Panax Ginseng based on uniform design: (1) Influence on the index of immune organs: Decoctions (Veratrum Nigrum + Panax Ginseng 0.53-8.5 g / kg) had no obvious effect on the index of immune organs of immunocompromised mice. (2) Influence on the ability of carbon clearance: Veratrum Nigrum could reduce the ability of Ginseng to enhance the phagocytic function (Panax Ginseng: Veratrum Nigrum <100: 1) in direct proportion. The strongest antagonistic effect of Veratrum Nigrum 083 g / kg (Panax Ginseng: Veratrum Nigrum = 9: 1). (3) Influence on blood routine: if Panax Ginseng: Veratrum Nigrum <100: 1, the effect of Ginseng to increase WBC and RBC would be counteracted by VeratrumNigrum (0. 034-0. 13 g / kg) without influencing the dose-effect curve of Ginseng. The strongest antagonistic effect of Veratrum Nigrum would be achieved when the total dose of decoctions was 4. 58 and 3. 48 g / kg (Panax Ginseng: Veratrum Nigrum = 9: 1). The effect of Ginseng to increase Hb would also be counteracted by Veratrum Nigrum but the dose-effect curve of Panax Ginseng would decline. [Conclusions] Within the dose range stipulated in the Pharmacopoeia, the body resistance strengthening function of Panax Ginseng may be reduced or counteracted by Veratrum Nigrum, and the intensity of effect changed with the imparity of proportions and dosages.