Abstract: Objective To investigate the e ffects of the lipid-lowering drugs in alleviating endothelial hyperplasia in the inferior vena cava (IVC) grafts in dogs.Methods The Dacron grafts seeded with autologous venous fragments were implanted into the IVC of 20 dogs, including 12 dogs receiving oral lipid-lowering drugs serving as the treatment group and t he other 8 with-out medication as the control group. The levels of total cholest erol (TC), low-density lipoprotein cholesterol (LDL-ch) and high-density lipopr otein cholesterol (HDL-ch) in the serum were measured regularly, and all the gra fts harvested to measure the thickness of the endothelium.Results The total pa tency rate of the IVC were higher in the treatment group (75%) than in the cont rol group (37.5%), and new endothelial lining was formed two weeks after the ope ration.Compared with the control group, the endothelial thickness of the graft s at the proximal (P<0.01), middle (P<0.05) and distal segments (P<0.05) of the IVC were all smaller in the treatment group, which also had lower serum LDL-ch and TC levels (both P<0.05) but with com-parable HDL-ch levels (P>0.05).Conclusion Administration of lipid-lowering drugs may reduce the level of serum LDL-ch and TC and the endothelial thickness of the grafts to improve the patency rate of the vessels.