The effect of Hippophae rhamnoides on hyperlipidemic rabbit serum (HRS) cultured smooth muscle cells (SMC) was observed in comparison with vitamin E(VE). The results show that Hippophae rhamnoides, much like VE, is also a potent antioxidant. It strongly decreases the MDA content in HRS cultured SMC and protect the cells from the injury of lipid peroxidation, and thus keeps the SMC growing and proliferating health. The results implicate that Hippophae rhamnoides is an effective antioxidant, and one of the important mechanisms of Hippophae rhamnoides in anti-atherosclerosis reported recently may be closely related to the action of anti-lipid peroxidation.