Abstract： Objective To explore the expression of MICA/B in human esophageal cancer,and to analyze its correlation with clinicopathological features.Methods The expression of MICA/B in 40 cases of esophagus carcinoma and corresponding normal esophageal mucosa tissues were examined by immunohistochemistry.Results The positive rate of expression of MICA/B protein in the esophageal carcinoma was 75.0％ (30/40),and that in the corresponding normal esophageal mucosa was 0 (0/40).Up-regulation of MICA/B expression was found in the esophageal carcinomas.The expression of MICA/B was related with histological grade of the esophageal carcinoma (P =0.012).Conclusion MICA/B protein plays an important role in the esophageal carcinogenesis,and my become a useful molecular marker for the diagnosis of esophageal carcinoma.