用人体胎盘型谷胱甘肽－Ｓ转移酶（ＧＳＴ－π）抗体，按ＡＢＣ免疫组织化学技术，检测了５０例食管癌、６８例癌前病变组织和５１例正常对照组织。结果表明：正常食管组织ＧＳＴ－π阳性率为３．９％；不典型增生组织为７７．９％；食管癌组织为８６．０％。不典型增生组织中ＧＳＴ－π阳性率随不典型增生程度增著而增加。同此可见，ＧＳＴ－π在食管癌及癌前病变组织中的表达为研究其发病机理和早期诊断提供了新的酶学指标，可以作为食管癌早期诊断的标志酶之一。 Using human placental glutathione-S transferase (GST-π) antibody, according to ABC immunohistochemical technique, 50 cases of esophageal cancer, 68 cases of precancerous lesion tissues and 51 normal control tissues were examined. The results showed that the positive rate of GST-π was 3.9% in normal esophageal tissues, 77.9% in atypical hyperplasia tissues, and 86.0% in esophageal cancer tissues. The rate of GST-π positivity in atypical hyperplasia increases with the degree of dysplasia. At the same time, the expression of GST-π in esophageal cancer and precancerous lesions provides new enzymological indicators for the study of its pathogenesis and early diagnosis, and can be used as one of the marker enzymes for the early diagnosis of esophageal cancer.