Objective: To investigate the expression and significance of HSP-70 (heat shock protein-70) in human diabetic cataract lens epithelial cells (LECs).Methods: The expression of HSP-70 was assayed using immunohisto-chemistry (streptavidin-alkaline phosphatase, S-P) in human diabetic cataract LECs (25 cases) and human nnormal LECs (7 cases).Results: There was significant expression of HSP-70 (x =26.42, p 0.01) in human diabetic LECs (25 cases) but there was no expression of HSP-70 in human normal LECs (7 cases).Conclusion: HSP-70 may play a critical role during the development and formation of human diabetic cataract.