Rehmannia Radix Preparata (RRP) used to nourish Eum and enrich blood for consumptive fever, aching, and limpness of the loins and knees, and to replenish essence for tinnitus, premature greying of beard and hair. In the present study, we studied about the protective effect of RRP on hydrogen peroxide-induced oxidative stress in human vascular endothelial cells. ECV304 cells were preincubated with RRP (100, 200, 300 and $400{mu}g/m{ell}$) for 12hr and then treated with $600{mu}M$ $H_2O_2$ for 12hr. The protective effects of RRP on $H_2O_2$-induced apoptosis in ECV304 cells was determined by using MTT assay, FDA-PI staining, flow cytometric analysis, caspase-3 activity assay, ROS assay and western blot. The results of this experiment showed that RRP inhibited $H_2O_2$-induced apoptosis and ROS production in ECV304 cells. Moreover, RRP increased ERK activation that decreased in $H_2O_2$-treated ECV304 cells, and inhibited p38 and JNK activation. Furthermore, RRP increased expression of heme oxygenase-1 (HO-1) in $H_2O_2$-treated ECV304 cells. Also, HO-1 protein expression induced by RRP was reduced by the addition of ERK inhibitor (PD98059) in $H_2O_2$-treated ECV304 cells. These results suggest that protective effect of RRP on $H_2O_2$-induced oxidative stress in ECV304 cells may be associated with increase of ERK activation and HO-1 protein, and reduction of p38 and JNK activation.