1目的　探讨脆性部位与原癌基因在乙型病毒性肝炎 (乙肝 )病人中的相关性及其与原发性肝癌发生的关系。2方法　用低叶酸、低小牛血清和较高 p H值培养方法 ,常规外周血染色体制片。对 2 0例乙肝病人 (病人组 )和 2 0例健康正常人 (对照组 )进行染色体脆性部位分析。 3结果　病人组检出 31种脆性部位 ,主要分布于 A,B,C组染色体 ,其表达率为 8.94% ,与正常对照组 (4.0 5 % )比较差异有显著性 (u=5 .83,P<0 .0 0 1)。脆性部位中有 12种与原癌基因位点重叠 ,重叠率为 38.7% .其中 2 q2 1与 2种原癌基因位点重叠 ;11q13与 5种原癌基因位点重叠。 4结论　乙肝病人脆性部位与原癌基因位点的重叠 ,更易诱使 HBV DNA整合 ,并可能对原癌基因的激活以至肝癌的发生起重要作用 1 Objective To investigate the relationship between the fragile parts and proto-oncogene in patients with hepatitis B (hepatitis B) and its relationship with the occurrence of primary liver cancer. 2 Methods Low folate, low calf serum and high p H value of culture methods, routine peripheral chromosomal chromosome preparation. 20 cases of hepatitis B patients (patient group) and 20 healthy controls (control group) were analyzed for chromosomal fragility. 3 Results The patient group detected 31 kinds of brittle parts, mainly distributed in chromosomes A, B and C, the expression rate was 8.94%, which was significantly different from the normal control group (4.05%) (u = 5.83, P <0 0 0 1). Twelve of the fragile sites overlap with oncogene loci, with an overlap rate of 38.7%, of which 2 q2 1 overlaps with two oncogenes and 11q13 overlaps with five oncogenes. 4 Conclusion hepatitis B patients with brittle parts of proto-oncogene overlap, more likely to induce HBV DNA integration, and may be oncogene activation and the occurrence of liver cancer play an important role