People tend to pay attention to the effects of smoking on the respiratory system, while ignoring the effects on the cardiovascular system, in fact, the effects of smoking on the cardiovascular system is not less than the effects on the respiratory system, and has been conclusive. Epidemiological surveys show that the incidence of coronary heart disease in smokers is about 2 times-10 times that of nonsmokers. Nicotine in tobacco can damage the vascular endothelium, causing it to lose its protective effect on the blood vessels, promoting the deposition of lipids in the vessel wall, and accelerating the process of atherosclerosis. Damage to the intima can also cause platelet adhesion and aggregation at the site, followed by fibrin deposition and the formation of microthrombi, promoting the occurrence and development of coronary heart disease. Nicotine can also cause coronary artery spasm and aggravate myocardial ischemia. Therefore, quitting smoking is of great significance in preventing coronary heart disease.