After intravenous administration of Se Pye San water extract in the rabbit, the change of plasma cortisol concentration, arterial blood $PCO_2$ and $PO_2$ was obtained such results as follows. 1. The plasma cortisol concentration in the control group was constant, but after intravenous administration of Se Pye San water extract at the dose of 0.2 ml/kg, the above concentration was increased significantly from 2 to 3 hours. Also, the above concentration was increased remarkably at the dose of 0.4 ml/kg from 1 to 4 hours. 2. After intravenous administration of Se Pye San water extract at each dose of 0.2 ml/kg and 0.4 ml/kg, arterial blood $PCO_2$ was decreased remarkably from 1 to 4 hours. 3. No change after intravenous administration of Se Pye San water extract at the dose of 0.2 ml/kg, while arterial blood $PO_2$ was decreased significantly at the dose of 0.4 ml/kg on 3 hours. As a results of the above, the therapeutic action of Se Pye San water extract effected with Jisu (止嗽), Jeong Cheon (定喘), Geo Dam, Cheong Yeol (淸熱) would be related with the increased both plasma cortisol concentration and arterial blood $PO_2$, and the decrease of arterial blood $PCO_2$.