Aloperine (ALO) is an alkaloid with anti-inflammatory,anti-tumor and anti-infection activities. However，its protective effects on hypoxia/reoxygenation (H/R) injured human umbilical vein endothelial cells (HUVECs) and involved mechanisms are unclear. In this study,hypoxia/reoxygenation injured HUVECs were constructed in vitro. The cells were divided into control group,hypoxia/reoxygenation group (H/R group) and different concentrations of aloperine (20,50 and 100 μmol/L) pretreated groups. Cell viability,the activity of lactate dehydrogenase (LDH) and superoxide dismutase (SOD),the content of methane dicarboxylic aldehyde (MDA),the level of intreleukin-1β (IL-1β) and tumor necrosis factor-α (TNF-α),and the protein expression of GRP78,XBP-1 and CHOP of different groups were measured. The results showed that compared with hypoxia/reoxygenation group,aloperine pretreatment could increase HUVECs viability and SOD,decreased LDH activity,MDA content,as well as levels of TNF-α and IL-1β (P<0.05). Aloperine pretreatment also down-regulated hypoxia/reoxygenation induced increase of GRP78,XBP-1 and CHOP (P<0.05). In summary,aloperine could improve the resistant of HUVECs against lipid peroxidation,decrease the levels of inflammatory cytokines and inhibit ERS related cell apoptosis,thus protect the HUVECs from hypoxia/reoxygenation injury.