The main components of the alcohol extraction from peony stamen was analyzed by high performance liquid chromatography. H₂O₂ induced human umbilical vein endothelial cells (HUVEC) cells to establish a damage model to study the protective effect of peony flower extract. Results: the alcohol extraction from peony stamen mainly contain three monomers, namely rutin, quercetin and paeoniflorin, with contents of 44.25%, 15.50% and 17.00%, respectively. The alcohol extraction from peony stamen can reduce the content of MDA in cells and culture medium, increase the activities of SOD, GPX and GSH content in the calls. The alcohol extraction of peony stamen can improve the antioxidant capacity of HUVEC.