Present experiment explored internal relationship between oxidized low density lipoprotein(OLDL) and endothelin (ET) on promoting cellular proliferation using cultured rabbit's vascular smooth muscle cells(VSMC).It was found that both could stimulate VSMC to proliferate;BQ123, antagonist of ETA receptor, could significantly inhibit the role that OLDL promoted VSMC to proliferate; 3H-TdR incorporation decreased by 13.3% compared with only OLDL group. Radial immunologic measurement on medium of cultured cells indicated that BQ123 could descended release of ET by 28.9% compared with only OLDL group.The results of immunocytochemistry were all compatible with above. It was suggested that the role that OLDL promoted VSMC to proliferate may be realized by ET in part in atherosclerotic pathogenesis.