Objective： To study the damaging effects of interleukin-6 (IL-6) and tumor necrosis factor (TNF) on human vascular endothelial cells (HVEC). Methods: A HVEC model was developed. After being incubated with IL-6, TNF and their antibody, HVEC morphological changes were observed, and the levels of lactate dehydrogenase (LDH) and angiotensin converting enzyme (ACE) in the culture fuild were measured. Results: TNF and IL-6 could cause enlargement in intercellular space, even the exfoliation of HVEC, moreover, ACE and LDH levels increased in a time- and dose-dependent manner. Conclusion: IL-6 and TNF have damaging effects on HVEC.