Objective To study the alternative expression and sequence of human elongation factor-1 (human EF-1 p31) during malignant transformation of human bronchial epithelial cells induced by cadmium chloride (CdCl2) and its possible mechanism. Methods Total RNA was isolated at different stages of transformed human bronchial epithelial cells (16HBE) induced by CdCl2 at a concentration of 5.0 μM. Special primers and probe for human EF-1 p31 were designed and expression of human EF-1 mRNA from different cell lines was detected with fluorescent quantitative PCR technique. EF-1 cDNA from different cell lines was purified and cloned into pMD 18-T vector followed by confirming and sequencing analysis. Results The expressions of human EF-1 p31 at different stages of 16HBE cells transformed by CdCl2 was elevated (P<0.01 or P<0.05). Compared with their corresponding non-transformed cells, the overexpression level of EF-1 p31 was averagely increased 2.9 folds in Cd-pretransformed cells, 4.3 folds in Cd-transformed cells and 7.2 folds in Cd-tumorigenic cells. No change was found in the sequence of overexpressed EF-1 p31 at different stages of 16HBE cells transformed by CdCl2. Conclusion Overexpression of human EF-1 p31 is positively correlated with malignant transformation of 16HBE cells induced by CdCl2, but is not correlated with DNA mutations. Objective To study the alternative expression and sequence of human elongation factor-1 (human EF-1 p31) during malignant transformation of human bronchial epithelial cells induced by cadmium chloride (CdCl2) and its possible mechanism. Methods Total RNA was isolated at different stages of Transfected human bronchial epithelial cells (16HBE) induced by CdCl2 at a concentration of 5.0 μM. Special primers and probes for human EF-1 p31 were designed and expressed of human EF-1 mRNA from different cell lines was detected with fluorescent quantitative PCR technique. EF-1 cDNA from different cell lines was purified and cloned into pMD 18-T vector followed by confirming and sequencing analysis. Results The expressions of human EF-1 p31 at different stages of 16HBE cells transformed by CdCl2 was elevated (P <0.01 or P <0.05). Compared to their corresponding non-transformed cells, the overexpression level of EF-1 p31 was averagely increased 2.9 folds in Cd-pretransformed cells, 4.3 folds in Cd -transformed cells and 7.2 folds in Cd-tumorigenic cells. No change was found in the sequence of overexpressed EF-1 p31 at different stages of 16HBE cells transformed by CdCl2. Conclusion Overexpression of human EF-1 p31 is positively correlated with malignant transformation of 16HBE cells induced by CdCl2, but is not correlated with DNA mutations.