Objective To explore the effect of Rhizoma Polygonati (RP) on arterial aging in naturally agingWistar rats. Methods SPF Wistar rats aged 72 weeks were divided randomly divided into 4 groups: an old group and RP low, medium, and high-dose groups (n = 14 rats per group). Another 14 male SPF Wistar rats aged 8 ~ 12 weeks were selected as the young group. Rats in the RP high, medium, and low-dose groups were administered with 4, 2, and 1 g / kg RP, respectively, by gavage, and rats in the old and young groups were given the same amount of distilled water once a day for 12 weeks. Seven rats from each group were sacrificed under anesthesia at weeks 4 and 12 and aortas were isolated. The relative smooth muscle cell (SMC) and collagen fiber (CF) contents were analyzed, total antioxidant capacity ( T-AOC ), glutathione peroxidase ( GSH-Px ), superoxide dismutase ( SOD), and malondialdehyde (MDA) levels were measured, and the expression levels of cell cycle-associated proteins in arterial tissue were detected by Western Blot. Results Rats in the old group showed obvious signs of vascular aging but there was no significant changes in arterial vascular tissue indexes in the old group with increased age. Aortas were obviously injured, relative contents of SMC and CF were significantly increased (P<0. 01), T-AOC, SOD, and GSH-Px contents were significantly decreased and MDA was increased (P<0. 01) in the old group compared with the young group at 4 and 8 weeks, and expression levels of cell cycle-associated proteins were significantly upregulated (P<0. 01). RP intervention significantly decreased the relative SMC and CF contents and MDA levels (P<0. 05 or P<0. 01) and significantly increased T-AOC,SOD,and GSH-Px (P<0. 05 or P<0. 01). Expression levels of cell cycle-associated proteins were also significantly decreased (P<0. 05 or P<0. 01). High-dose RP had the greatest effect. Conclusions Arterial aging is relatively stable in the short term in naturally aging rats. RP could delay arterial aging in naturally aging rats by regulating the level of oxidative stress and the expression of cell cycleassociated proteins.