Abstract: Objective To investigate the protective effect of taurine on chromo some damage of human derived fetal hepatocytes(L-02 cells)induced by benzo(a)pyrene(B(a)P).Methods L 02 cells were randomized divided into 5 groups:blank control group(Ⅰ);solvent control group(Ⅱ);B(a)P group(Ⅲ):exposed to B(a)P at concentration of 12.5,25,50 mol/L,in culture medium for 24 ho urs;taurine group(IV):exposed to taurine at the concentration of 1.0,2.0,4 0mmol/L in culture medium for 24 hours;taurine preventive group(V):exposed to taurine at three different concentration in culture medium for 24 hours and treated further for 24 hours by add ing 25 mol/L B(a)Pinto the culture media.Chromo some damage was detected by cytok inesis block mic ronucleus assay(CBMNT).The frequencies of MN(%)and nucleidivision index(NDI)were calculated.Results Compared with the blank control,taurine at concentrations of 2.0 and 4.0mmol/L induced a significant decrease in M N frequencies and an increase in NDI in L-02 cells.Compared with the solvent control,B(a)Pat concen trations of 12.5,25 and 50 mol/Linduced a significant enhancement of MN frequencies and reduce in ND I.Compared with the 25 mol/LB(a)P group,pretreatment with taurine could induce a significant decrease in M N frequencies and an increase in NDI in L-02 cells.The reductions of MN frequency and NDI showed a dose effect manner.Conclusion B(a)P could induced chromo some damage in dose effectmanner.Taurine could play a protective role in hepaticcy to toxicity induced by B(a)P.