Objective: To investigate the correlations among the expressions of hypoxia-inducible factor-1α (HIF-1α), vas-cular endothelial cell growth factor (VEGF) and microvessel density (MVD), and their relationships to the clinicopathologic characteristics of esophageal squamous cell carcinomas (ESCC). Methods: The expressions of HIF-1α, VEGF and MVD were detected by immunohistochemical method in 45 cases of ESCC, 30 intraepithelial neoplasia and 35 normal esophageal mucosal epithelia tissues. The correlations among the expressions of HIF-1α, VEGF and MVD, and their relationships to the clinicopathologic features of ESCC were analyzed. Results: The rate of positive expression of HIF-1α and VEGF which were 80% and 84% in ESCC were significantly higher than those in intraepithelial neoplasia and normal esophageal ucosal epi-thelium tissues (P<0.01) and so did the MVD value which was 71.10±15.02 in ESCC (P<0.01). The expression of HIF-1αand VEGF were positively correlated with the depth of tumor invasion, lymph node metastasis and TNM staging of ESCC.The expressions of HIF-1α were positively correlated with the expressions of VEGF and the value of MVD. Conclusion: Overexpression of HIF-1α is found in ESCC. HIF-la may induce the angiogenesis in ESCC by upregulating the transcription of VEGF gene. It may play an important role in the carcinogenesis and aggression in ESCC, HIF-1α, VEGF and MVD may be a useful marker for evaluating the biological behaviors of ESCC.