Objective To investigate the effects of Stichopus variegatus mucopolysaccharide on plasma nitric oxide (NO) and serum endothelin(ET) after angioplasty in rabbits. Methods 50 New Zealand rabbits were randomly divided into four groups: Stichopus group, simvastatin group, model group and normal group. Endothelium of iliac arteries in Stichopus group, simvastatin group and model group were denuded by balloon catheter and the rabbits were fed with 2%cholesterol, 3%lard and 3%yolk mixed forage for six weeks, and then, atherosclerotic stenosis was showed by iliac angiography.When transluminal balloon angioplasty was done, from then on the feeds was changed from high cholesterol to ordinary forage. Stichopus (0.5g?kg -1?d -1) and simvastatin (0.5mg?kg -1?d -1) were given by gastric canal. While NaCl solution (0.9%) was given in model group. All rabbits were fed in separate cages and free drinking. After four weeks since transluminal balloon angioplasty, blood was collected from carotid artery to measure the changes of concentrations of endothelin(ET) and nitric oxide(NO). Examination of pathology by optical and electron microscope were done at same time. Results After four weeks since transluminal angioplasty, the concentration of plasm ET in model group increased significantly compared with the normal group(114.86?24.89 ng?L -1 vs 75.62?9.68 ng?L -1) and serum NO decreased significantly(37.50? 12.79?mol?L -1 vs 106.37?18.01 ?mol?L -1).The concentration of plasm ET in model group was higher than that in the simvastatin groups and Stichopus groups(114.86?24.89 ng?L -1 , 81.08?14.71 ng?L -1 and 83.34?11.41 ng?L -1 ,respectively),and the concentration of serum NO decreased obviously(95.63?8.62 ?mol?L -1,98.80?9.06 ?mol?L -1 and 37.50?12.79 ?mol?L -1,respectively). Conclusion After iliac arterial TA the concentrations of plasm ET were increased and the serum NO were decreased, the endothelial function fell into disorder. The Stichopus variegatus mucopolysaccharide had the effects of improving the endothelial function after angioplasty in rabbits by adjustment of plasm ET and serum NO.