目的建立ＣＨＬ３Ａ４细胞系为某些遗传毒性化合物的代谢途径研究提供模型细胞系，并用于新合成化学物质的致突变性检测。方法应用ＲＴＰＣＲ和ＤＮＡ重组技术从人肝组织中克隆细胞色素Ｐ４５０３Ａ４基因的ｃＤＮＡ至ＢｌｕｅｓｃｒｉｐｔＭ１３载体上，经限制性内切酶图谱分析和克隆片段部分序列测定，证实为ＣＹＰ３Ａ４ｃＤＮＡ。然后构建真核细胞重组表达质粒ｐＲＥＰ９３Ａ４，导入中国仓鼠ＣＨＬ细胞。结果建立了ＣＨＬ３Ａ４转基因细胞系，双核细胞微核试验证明该细胞系能代谢活化黄曲霉毒素Ｂ１（ＡＦＢ１）、杂色霉菌毒素（ＳＴＣ）、环磷酰胺（ＣＰＡ）。结论所建ＣＨＬ３Ａ４细胞系确实能表达人细胞色素Ｐ４５０３Ａ４，并能代谢活化ＡＦＢ１、ＳＴＣ、ＣＰＡ。 Objective To establish a cell line of CHL3A4 cell line for the study of metabolic pathways of some genotoxic compounds and to test the mutagenicity of new synthetic chemicals. Methods The cDNA of cytochrome P4503A4 gene was cloned from human liver tissue into Bluescript M13 vector by RTPCR and DNA recombinant technology. The CYP3A4 cDNA was confirmed by restriction endonuclease mapping and partial cloning fragment sequencing. Then construct eukaryotic recombinant plasmid pREP9  3A4, introduced into Chinese hamster CHL cells. Results The CHL3A4 transgenic cell line was established and the micronucleus test of the dual cell nucleus demonstrated that the cell line can metabolize aflatoxin B1 (AFB1), stained mycotoxins (STC) and cyclophosphamide (CPA). Conclusion The constructed CHL3A4 cell line can indeed express human cytochrome P4503A4 and can metabolically activate AFB1, STC and CPA.