Aim To investigate protective effection of Quercetin （Que） on human umbilical vein endothelial cells （HUVEC） from oxidative stress injury in rats and its mechanism. Methods Oxidative stress model of HUVEC was established by H₂O₂. Then, MTT assay was used to investigate the cell proliferation ability. The content of lactate dehydrogenase （LDH）, malondialdehyde （MDA）, superoxide dismutase （SOD） were determinated by kits. Flow cytometry was used to detect cell apoptosis. The protein expression of PTEN, Akt, phospho-Akt and Bcl-2 were detected by Western Blot.Results H₂O₂ can decrease HUVEC survival, while 10, 20 μmol/L Que significantly increase cell viability （P<0.05） Que treatment can significantly increase SOD activity, while significantly decrease MDA and LDH levels （P<0.05）, and reduce their rate of apoptosis compared with H₂O₂ treatment group. Finally, Que can effectively increase PTEN and reduce p-Akt, Bcl-2 expression. Conclusion High-dose Que can effectively protect HUVEC cells against H₂O₂ damage this effect may be related to the role of PTEN-Akt pathway by inhibiting endothelial cell apoptosis.