Objective To investigate the anti-leukemia mechanism of Zhebei Huangqin Decoction in NOD/SCID subcutaneous tumor-bearing mice.Methods Twenty NOD/SCID mice were injected subcutaneously with kasumi-1 cell, then divided randomly into model group, chemotherapy group, CSFD group and DA+CSFD group.The tumor-bearing mice were intervened by distilled water, daunorubicin+cytarabine, Zhebei Huangqin Decoction and Chinese and Western medicine.The living state, body weight, transplanted tumor volume and weight, and blood routine changes of mice in each group were observed.The expression levels of wip1 mRNA and p53 mRNA in transplanted tumor cells were detected by RT-PCR.The expression level of wiP1 and p53 were detected by real-time PCR.Results The volume of subcutaneous transplanted tumor in each group increased gradually, of them the DA+CSFD group had the smallest tumor volume and weight（P<0.05）;the platelets in DA+CSFD group were lower than before（P>0.05）,and that in the other three groups were significantly higher than before（P<0.05）;compared with the model group, the expression of wip1 mRNA in the CSFD group was decreased, and the expression of p53 mRNA in the CSFD group was significantly up-regulated（P<0.01）,that in the DA group was down-regulated and that in the DA+CSFD group was the same as the model group.Conclusion CSFD could reduce the expression of wip1,and promote the recovery of p53 transcription regulation function, inhibit the proliferation of leukemia cells and reverse part of drug resistance.