Abstract: Objective:To explore the role of Notch- 1 in the tumorigenesis and progression of human esophageal carci-noma and its clinical significance. Methods:Esophageal squamous cell carcinoma (ESCC) and adjacent normal tissue (the normal esophageal mucosa being at least 5 cm apart from the edge of the tumor) specimens were collected in our hospital between April2008 and September 2008. A total of 41cases were examined by RT-PCR to detect the relative expression intensity of Notch- 1 gene at the mRNA level Also, the differences in Notch-1 relative expression intensity between tumor and normal tissue were analyzed. Moreover, its relationship to the clinicopathological features, such as depth of tumor inva-sion (T), lymph node metastasis (N), TNM stage, and degree of differentiation, was also assessed. Results: (1) Notch- 1 electrophoretic bands could be seen in all specimens, indicating that Notch-1 gene was expressed in all specimens at the mRNA level. (2) Semi-quantitative analysis showed that the relative expression intensity of Notch- 1 in ESCC was 0.51±0.37, while in adjacent normal tissue it was 0.32± 0.20, with a significant difference ( t=3.52, P=0.001 ). (3) After stratification by the clinicopathologic features mentioned above, significant differences in Notch-1 expression between ESCC and adja-cent normal tissue were found in all sub groups. However, in ESCC, there was no significant difference among sub-groups. Conclusion:Notch- 1 may play a role in ESCC tumorigenesis but may be unrelated to the progression of ESCC.