本文应用ＰＣＲ技术和寡聚核苷酸探针检测苯作业工人外周血白细胞中Ｋｉ─ｒａｓ癌基因第１２位密码子点突变。４１名接触苯工人和４１名对照工人中只有１例接苯工人发生ＧＧＴ→ＴＧＴ（Ｇｌｙ→Ｃｙｓ）突变，该女工苯作业工龄６年，连续三次（均间隔三个月）白细胞计数均呈低下状态，但其他血液学指标未见明显异常。初步探讨了Ｋｉ─ｒａｓ基因点突变检测作为苯白血病的生物标志和职业人群早期监护指标的可能性。 In this study, PCR technique and oligonucleotide probe were used to detect the codon 12 mutation of Ki -ras oncogene in peripheral blood leukocytes from benzene-exposed workers. Only 41 of 41 exposed benzene workers and 41 control workers received GGT → TGT (Gly → Cys) mutations. The female worker’s benzene working length was 6 years and the white blood cell count was low for three consecutive times (every 3 months) State, but no other hematological indicators of significant abnormalities. The possibility of Ki -ras gene point mutation detection as a biomarker of leukemia and an early monitoring indicator of occupational groups was initially discussed.