Objective:To observe the effect of Jianpi Jiedu Decoction on the mRNA expression of Bax and Bcl-2 in subcutaneous transplanted tumor of nude mice. MethodsHCT8/V cells were subcutaneously injected into the nude mice to establish model. Then 32 successful modeling mice were randomly divided into four groups and 8 in each group. The blank group was treated with intraperitoneal injection of 0.9% NaCl, the chemotherapy group was treated with intraperitoneal injection of vincristine, the Chinese medicine group was given Jianpi Jiedu Decoction by means of intragastric administration, the combination group was given vincristine with intraperitoneal injection and Jianpi Jiedu decoction with intragastric administration. The tumor weight and inhibition rate of subcutaneous transplanted tumor in each group were measured, the pathological changes of tumor tissues were observed by light microscope, and the mRNA expression of Bax and Bcl-2 were determined by Real-time PCR.  Results:Compared with the blank group, the tumor weight of the chemotherapy group, Chinese medicine group and combination group was significantly reduced, with statistically significant difference(P<0.01); compared with the chemotherapy group, the tumor weight of the Chinese medicine group and combination group was significantly reduced, with statistically significant difference(P<0.01); compared with the blank group, the inhibition rate of tumor in the chemotherapy group, Chinese medicine group and combination group were 22.84%, 38.44%, 51.53% respectively, and the effect of the combination group was best. Compared with the blank group, the Bax mRNA expression of the chemotherapy group, Chinese medicine group and combination group was increased significantly (P<0.05, P<0.01) and the Bcl-2 mRNA expression was significantly decreased (P<0.01); compared with the chemotherapy group, the relative expression level of Bax mRNA in the Chinese medicine group and the combination group was higher than that in the chemotherapy group(P<0.05,P<0.01), the relative expression level of Bcl-2 mRNA in the Chinese medicine group and the combination group was lower than that in the chemotherapy group (P<0.01).  Conclusion:Jianpi Jiedu Decoction promote the apoptosis of colorectal cancer cells by up-regulating the mRNA expression of Bax and down-regulating the mRNA expression of Bcl-2, which shows synergistic effect with chemotherapy drug.