Title: A randomized, double-blind, multi-centered, placebo-controlled trial to examine effects of of Heart-protecting Musk Pill on clinical outcomes in patients with chronic stable coronary artery disease Objective: To examine effects of of Heart-protecting Musk Pill, a traditional Chinese medicine, on clinical outcomes in patients with chronic stable coronary artery disease The study hypothesis: The null hypothesis: the combined incidence of cardiovascular death, nonfatal myocardial infarction, nonfatal stroke in the treatment group is the same as that in control group. The alternative hypothesis: the combined incidence of cardiovascular death, nonfatal myocardial infarction, nonfatal stroke in the treatment group is different from that in control group. Sample size: 2700 patients will be randomized, 1350 in treatment group and 1350 in placebo group. Number of sites: 99 sites in China Study drugs: Heart-protecting Musk Pill and the matching placebo pills. Design: A randomized, double-blind, multi-centered, placebo-controlled trial. Patients will be randomized to treatment group and placebo group after screening and get corresponding treatment as follow. Treatment group: Standard treatment for coronary artery disease plus 2 Heart-protecting Musk Pills each time, three times a day by mouth for 24 months. Control group: Standard treatment for coronary artery disease plus 2 placebo pills each time, three times a day by mouth for 24 months. Patients will be followed up at baseline, 1, 3, 6, 9, 12, 18, 24 months after randomization. During follow-up period, patients could undertake PCI or CABG if angina get out of control or evidence of ischemia aggravated is found.