Objective To study the changes of activities of phase Ⅰ and Ⅱ drug-metabolic enzymes in the spleen of rats with spleen-kidney yang deficiency syndrome.Methods The rat model of spleen-kidney yang deficiency syndrome was established by gastric gavage of Radix et Rhizoma Rhei decoction combined with injection of hydrocortisone for 17 continuous days.And then we detected the activities of 6 kinds of phase Ⅰ drug-metabolic enzymes of CYP2C19,CYP2D6,CYP2C9,CYP1A2,CYP2C8,CYP3A4,and 4 kinds of phase Ⅱ drugmetabolic enzymes of phenol sulfotransferase (PST),uridine diphosphate glucuronosyl transferase 1 (UGT1),glutathione transferase (GST),estrogen sulfotransferase (SULT1E1) in the spleen.Results Compared with the normal control group,the activities of PST,UGT1,GST and SULT1E1 in the model group were significantly decreased (P ＜ 0.05 or P ＜ 0.01),and the activity of CYP1A2 was significantly increased (P ＜ 0.01),while CYP2C19,CYP2D6,CYP2C8,CYP3A4,CYP2C9 enzymes showed no obvious changes(P ＞ 0.05).Conclusion The activities of splenic drug-metabolic enzymes,in particular the phase Ⅱ enzymes,are significantly varied under the state of spleen-kidney yang deficiency.