Objective To study the effect of Zhimaikang Granules (Granules for lipid abnormality) on atherosclerosis of hyperlipidemia patients of phlegm turbidity retention type.Methods Totally 120 hyperlipidemia patients were randomized into treatment group and control group, 60 cases in each. The treatment group was administered Zhimaikang Granules, each time 1 bag, twice a day. The control group was given Simvastatin Tablets, oral taking before sleeping. Both groups were treated for 45 days. Changes of superoxide dismutase (SOD), malondialdehyde (MDA), and nitric oxide (NO) were observed.Results After treatment, activity of NO and SOD were significantly higher than before in both groups (P0.05).Conclusion Zhimaikang Granules was proved to enhance the activity of antioxidase, promote anti-free radical reactions, inhibit lipid peroxidation and protect endothelial cells in atherosclerosis patients.