Objective To explore the role of tumor inhibition of enhancer binding protein C/EBPα in the leukemic mice. Methods BALB/c nude mice were randomly divided into three groups. Three kinds of cells including pEGFP-C/EBPα-K562 cells, pEGFP-K562 cells and K562 cells as the control were injected into mice separately through the subcutaneous and tail vein, and subcutaneous tumors and leukemic models were formed. The changes of tumors were observed and the apoptosis of cells was detected by TUNEL; The capacity of proliferation of leukemia cells was observed in the bone marrow and the peripheral blood by Wright-Giemsa staining. The expression of genes of related to proliferation was detected by RT-PCR. Results The quality and the max diameter of tumors in the pEGFP-C/EBPα-K562 group were smaller than that of pEGFP-K562 group and K562 control group [(2.4±0.1) g vs (5.1±0.3) g and (5.7±0.4) g, both P ＜0.05; (11+2)mm vs (19+3) mm and (23+3) mm, both P ＜0.05]. More apoptosis cells were found in the pEGFP-C/EBPα-K562 group leukemic cells were found in the peripheral blood of leukemic models, and the proliferation of leukemic cells in the pEGFP-C/EBPo-K562 group were lower than that of other groups, accompany by the conspicuous cell differentiation. p53 was significantly elevated by RT-PCR, while down-regulated of c-myc.Conclusion Enhancer binding protein C/EBPα promote the apoptosis of cells and inhibit the proliferation of leukemia cells in leukemia mice, and further induce the cell differentiation. The inhibition of enhancer binding protein C/EBPα in the leukemia may have effect through the regulation of related genes.