This is a double blind randomized control trial. Coronary artery disease patients (stable and unstable CAD) with stenosis equal to or more than 50% in at least one of the main coronary arteries and patients who receive PTCA (angioplasty) will be selected. Patients with diabetes, thyroid disorders, liver and kidney disease are excluded from this study.After obtaining the consent of those eligible, randomly selected into two groups receiving the L-carnitine supplement and placebo.Intervention group will receive two L carnitine 500 mg tablets (made in kaern company- Iran) twice a day for 12 weeks and control group will receive quite similar tablets containing soluble starch with the same dose and time-consuming. At the beginning and end of the study 10 ml blood venous sample after 12-14 hours of fasting will be obtained. Biochemical variables including inflammatory factors (hs-CRP), oxidative stress (Nytrotirosine and myeloperoxidase), total antioxidant capacity (TAC) at baseline and again at the end of the study (12 weeks) will be examined. Anthropometric measurements and body composition (including height, weight, BMI, waist circumference and hip circumference, body fat mass, percent fat-free mass, etc.) at the beginning of the trial and the end of the sixth and twelfth weeks will be checked. To obtain information about food intake, 24-hour recall questionnaire for 3 first days of study and at the end of the sixth and twelfth weeks (for 2 typical day and a holiday) will be completed through interviews.