Abstract： Objective To investigate the effects of aerobic rehabilitation training combined with external counter-pulsation(ECP)on postoperative recovery in elderly patients with coronary artery disease(CAD)who have undergone percutaneous coronary intervention(PCI),and its impact on collateral circulation and endothelial function.Methods A total of 208 elderly CAD patients treated with PCI from January to December,2021 were randomly divided into two groups:control group(48 patients)receiving routine nursing care combined with ECP,and observation group(48 patients)re-ceiving aerobic rehabilitation training combined with ECP.Cardiopulmonary function indicators,endothelial function,col-lateral circulation,exercise tolerance indicators,and quality of life were assessed before and after the intervention.Results After 3 months of intervention,the observation group showed significant improvements in cardiopulmonary func-tion indicators such as sub-threshold metabolic equivalents,peak oxygen uptake,peak oxygen pulse,and sub-threshold metabolic equivalents compared to the control group(P＜0.05).The observation group also demonstrated higher values in heart function indicators such as left ventricular ejection fraction,cardiac output,and maximum heart rate(P＜0.05).Endothelial function indicators,including flow-mediated brachial artery endothelium-dependent dilation and brachial ar-tery endothelium-independent dilation,and collateral circulation scores were significantly better in the observation group(P＜0.05).The observation group exhibited lower scores in exercise tolerance indicators like heart rate-blood pressure product,perceived fatigue grade,and Borg scale,and had longer exercise duration(P＜0.05).The quality of life scores were also significantly higher in the observation group compared to the control group(P＜0.05).Conclusion Aerobic rehabilitation training combined with ECP for elderly CAD patients post-PCI significantly enhances recovery of cardiopul-monary function,improves cardiac collateral circulation and endothelial function,boosts exercise tolerance,and elevates quality of life.This effective rehabilitation approach has significant clinical application value.