OBJECTIVE: To investigate the expression and significance of HSP27, HSP60, HSP70 and HSP90 alpha in esophageal squamous cell carcinoma (ESCC) and tissues along the incision margin (TIM). METHODS: The presence and the level of expression of HSP27, HSP60, HSP70 and HSP90 alpha were determined in 168 specimens from ESCC and 42 from tissues along TIM by EnVision immunohistochemistry and Western blotting, to compare their positive staining rates and explore the correlation between their expressions and clinicopathologic features in ESCC. RESULTS: The positive staining rates of HSP27, HSP60, HSP70 and HSP90 alpha in ESCC and TIM were 62.0% and 42.1%, 92.7% and 63.2%, 57.9% and 22.2%, and 33.7% and 18.5%, respectively. There was very significant difference between the expression of HSP60 and HSP70 in ESCC and TIM (P < 0.01), but not significant about HSP27 and HSP90 alpha (P > 0.05). The positive staining rate of HSP27 declined with the lower grade of differentiation of ESCC (P < 0.05). CONCLUSION: The present findings suggest that the expression of HSPs of different molecular weight in ESCC and TIM is a common event. The level of expressions of HSP60 and HSP70 are higher than those in TIM. HSP60 and HSP70 expression correlated with the biological behavior of ESCC. The expression of HSP27 was positively correlated to the grade of differentiation of ESCC. Overexpression of HSP27 may be associated to the differentiation of squamous cell carcinoma.