Abstract: Objective To determine the effects of oxidative stress reaction on intima hyperplasia after autologous vein grafting. Methods Seventy female SpragueDawley(SD) rats were randomly divided into a control group(n=10) and an experimental group (n=60). The experimental group was then divided into six time points of one day; one, two, four, and six weeks; and two months after surgery; with 10 rats for each time point. Autologous vein grafting models were established. At each time point the designated rats were anaesthetized, and the grafts were isolated and stained with HE. The same length of external jugular vein was cut from each rat in the control group. The neointima to tunica media area ratios (I/M) were measured with acomputerized digital image analysis system. Nuclear factorkappa B (NF-κB) and copper zinc superoxide dismutase (CuZnSOD) were detected byimmunohistochemistry. The concentration of malondialdehyde (MDA) in serum was analyzed by colorimetry. Results In the control group, expression levels of NF-κB and CuZnSOD were low. In the experimental group, expression of NF-κB increased after the operation and peaked two weeks later. The plateau was sustained for about one month, and then the level of expression declined gradually, reaching the baseline at the twomonth time point. The expression of CuZnSOD increased gradually after the operation and peaked one week later, then declined to the normal level after 2-3 weeks at the plateau. In the control group, the concentration of serum MDA was 4.966±1.346 nmol/ml. In the experimental -group, the-MDA concentration increased dramatically after the operation, then-declined from its highest level at the oneday time point (21.161±2.174 nmol/ml) to the normal level at two months (6.208±2.908 nmol/ml) after the operation (P<0.05). In the control group, I/M was 0.2096±0.0253, while in the experimental group, it was higher one week after the operation (0.6806±0.0737) and peaked at four weeks (1.4527±0.0824), falling to 1.0353±00656 at six weeks and 0.9583±0.0516 attwo months (P<0.05) for the experimental and control groups). Conclusion Endothelial cell injury initiates an oxidative stress reaction after autologous vein grafting and augments inflammation by activating NF-κB, thus playing an important role in inducing restenosis of the grafted vein.