Aim To investigate the effect of Uncaria alkaloids on protecting rat vascular endothelial cells and inhibiting cell senescence. Methods Aging model of rat aortic endothelial cells(REAC) was established by D-galactose.Treated with Uncaria alkaloids and Captopril,separately,then,the aging vascular endothelial cell morphology were observated by scanning electron microscopy,vascular endothelial cell senescence rate was determinated by β-galactosidase staining method,and telomerase activity was determinated by PCR-ELISA method. Results REAC cell morphology treated with Uncaria alkaloids or captopril was significantly improved,β-galactosidase expression and telomerase activity were significantly decreased(P<0.05).The effects of each dose group of Uncaria alkaloids were: medium dose> low dose> high dose,suggesting that high dose of Uncaria alkaloids(> 400 mg/L) may have a certain degree of cytotoxicity,and the best dose of Uncaria alkaloids dose was 200 mg/L. Conclusion Uncaria alkaloids can inhibit rat aortic endothelial cell senescence,and protect vascular endothelium.