Objective: To explore the therapeutic effect of Roxithromycin in coronary artery disease (CAD). Methods: A total of 60 CAD patients with IgM antibody positive of chlamydia pneumoniae(Cp) were divided into Roxithromycin group (30 cases, treated with Roxithromycin 150 mg, bid) and control group (30 cases, no treated with Roxithromycin). IgM antibody of Cp was re-examined after therapy one month. The patients were followed up one year. Results: There were 3 cases (10%) occurred with events of cardiovascular in Roxithromycin group, but it were 10 cases (33%) in control group. Incidence of cardiovascular events of Roxithromycin group was less than control group (P0. 05). Tilers of Cp were no significantly difference between two groups before and after therapy. Conclusion: Roxithromycin can decrease the incidence of cardiovascular events in CAD patients.