Abstract: Objective 　To investigate the relationship between the expression of t ryptase and chymase and clinical pathological features of esophageal carcinoma. Methods 　Tumorous tissues f rom 71 patient swith esophageal carcinoma were collected and stained with immunohistochemical technique. The gender, histological grades, depth of invasion, lymph node metastasis rate, t ryptase and chymase of these patients were analyzed. Results 　Mast cells resided predominantly in the marginal area of the tumor. The expression of t ryptase, but not chymase was negatively correlated to the differential degree and the depth of tumor invasion of the esophageal carcinoma. Conclusion 　There are correlations between the positive expression of t ryptase in mast cells and esophageal cancinoma biological behaviour. Mast cell with the positive expression of t ryptase infilt rating the mat rix of the tumor may play an important role in preventing the invasion of esophageal cancinoma and mast cells may be of value to predict the prognosis of esophageal cancinoma.