Chronic myelogenous leukemia (CML) is a clonal myeloproliferative disease of transformed hematopoietic progenitor cells. It is now clear that the chimeric bcr/abl P210(bcr/abl) fusion protein, which is generated by the reciprocal translocation t (9; 22), inhibits apoptosis and increase proliferation. P210(bcr/abl) plays a central role in the pathophysiology of CML. The purpose of this study was to construct a cell line model that bcr/abl expression can be regulated by Tet-off inducing-expression-system. The full-length b3a2 bcr/abl cDNA was subcloned into the pTRE2hyg expression vector to construct the pT2-P210 plasmid. 293 cells were firstly transfected with Tet-off plasmid and the clone that the Tet-off system can work effectively after transfected with pTRE2hyg-LUC was selected by luciferase activity assay. The pT2-P210 plasmid was then transfected into the selected clone and cells were then selected for hygromycin B and G418 resistance. The results showed that individual subclones expressing bcr/abl after withdrawing doxycycline were 293pT2-P210 cell line. In conclusion, selected 293pT2-P210 cells are cells that bcr/abl expression can be regulated by Tet-off inducing-expression-system. They are suitable thoroughly to study the function of bcr/abl fusion gene and its signal regulation mechanism.