Objective　To findout a good method for malignant transformation of human bronchial epithelial cells 16HBE cell induced by anti-benzo (a) pyrene-trans-7,8-dihydrodiol-9,10-epoxide (anti-BPDE) using the objective and simple index:colony forming frequency of cells in semisolid agar culture medium,and to establish a best model of malignant transformation of 16HBE cells.Methods　The tests on viable rate and colony formation of 16HBE cells were carried out to determine the exposure doses of anti-BPDE.The l6HBE cells were treated once or several times by anti BPDE at different doses and the transformed foci were observed and assessed at the different stages during the period of the whole experiment.The malignant features of transformed 16HBE cells with a good dose-response relationship were identified by the method of semisolid agar culture.The anti-BPDE induced colony forming frequencies of 16HBE cells in semisolid agar medium in each dose group were statistically compared.Results　The best method for malignant transformation of 16HBE cells induced by anti-BPDE was that the 16HBE cells were intermittently treated several times with anti-BPDE at doses of 0.1,0.5,1.0 and 2.0 μmol/L respectively and were inoculated for 15 generations,the related colony forming frequencies were 2.0‰,5.5‰,7.0‰ and 10.5‰respectively with a significant dose-response relation ship and a good linear correlation (r=0.9741,P＜0.05).Conclusion　The research infered that the malignant transformation of human bronchial epithelial cell-16HBE cells could be induced successfully by anti-BPDE,a suitable model could be established by anti-BPDE also.