Objective To evaluate the effectiveness and safety of simvastatin 40 mg daily use in treatment of coronary heart disease. Methods The study was designed as before-after study in the same patients. One hundred and sixty seven patients with coronary heart disease were prescribed simvastatin 40 mg daily for 3 and 6 months. Total cholestero (TC), low-density lipoproteins cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), triglycerldes (TG), ALT and creatine kinase (CK) in serum before therapy and at the end of 3 months and 6 months treatment were dectected. Continuous data were analyzed by standard difference of blocked randomization and described by mean±SD. Dunnet-t test was used for multiple comparison of trial and control groups. Statistical difference was set up at P＜0.05. Success rate was assessed by chi square test at the end of 3 and 6 months treatment. Results Simvastatin 40 mg/d significantly decreased the level of TC (P＜0.000 5), LDL-C (P＜0.000 5), TG (P＜0.05), and could elevate HDL-C (P＜0.05). There were 39.5% of patients whose LDL-C reduced below 70 mg/dl. One patient whose CK raised 5.6 times of upper line of normal range and 4 patients whose ALT raised more than 2 times of upper line of normal range withdrew. The reliability of simvastatin 40 mg/d was relatively good. Conclusions Simvastatin 40 mg/d could significantly improve the lipid profile, and is relatively reliable in treatment of coronary heart disease.