Abstract: Objective To study the outcome and risk factor for coronary heart disease (CHD) in young and elderly patients after coronary artery bypass grafting (CABG). Methods Four hundred and thirty-seven CHD patients (51 with their age ≤45 years and 386 with their age ≥65 years) who underwent CABG in our hospital from May 2009 to May 2012 served as a CHD group and 315 non-CHD patients (68 with their age ≤45 years and 247 with their age ≥65 years) who underwent heart surgery in our hospital from May 2009 to May 2012 served as a non-CHD group in this study.Risk factors for CHD before operation, intraoperative and postoperative complications and mortality were compared between the two groups and correlation between risk factors for CHD was analyzed. Results The respiratory auxiliary time, ICU and hospital stay time were significantly shorter in CHD patients with their age ≤45 years than in those with their age ≥65 years after CABG (P＜ 0.05).Male, family history of CHD, smoking, high BMI, LDL and HDL were the risk factors for CHD in patients with their age ≤45 years. Conclusion The outcome is better in CHD patients with their age ≤45 years than in those with their age ≥65 years after CABG.Male, family history of CHD, smoking, high BMI, LDL and HDL are the risk factors for CHD in patients with their age ≤45 years.Such patients should be educated and treated according to their controllable factors.