Quitting smoking reduces the incidence and mortality of diseases such as chronic obstructive pulmonary disease, lung cancer, coronary heart disease, stroke, peripheral vascular disease, and gastric and duodenal ulcers. Quitting smoking also reduces the risk of passive smoking to those around you, especially their family members and co-workers. Tobacco is one of the major threats to human health, and physicians have a sacred responsibility to protect the rights of human health, from this perspective, tobacco control is one of the responsibilities of physicians. As a doctor, first of all, should be non-smoking. However, in China, doctors are more serious smokers than the general public, and have become the antithesis of tobacco control, which is clearly in conflict with the responsibility and image of doctors. The level of smoking reflects the level of social civilization, and smoking rates in the United States, Canada, and some developed countries in Western Europe have begun to gradually decline. There are benefits to quitting at all ages, and it is better to quit early than late, and better to quit than not to quit at all. Smoking accelerates the rate at which lung function decreases with age, and quitting increases lung function mildly, reversing the rate at which it decreases. quitting before age 30 reduces the risk of lung cancer by 90%. Five years after quitting, the increased risk of oral and esophageal tumors due to smoking is reduced by half. The risk of heart disease decreases even more rapidly after quitting, with deaths from smoking halved within 1 year and the absolute risk similar to that of never-smokers within 15 years. WHO has included tobacco dependence as a disease in the International Classification of Diseases (ICD-10) (F17.2, a psychoneurological disease), recognizing tobacco as the greatest threat to human health today. Tobacco dependence, also known as nicotine dependence, is characterized by an uncontrollable urge to seek nicotine and the compulsive, continuous use of nicotine to experience the euphoria and pleasure it brings and to avoid possible withdrawal symptoms. The essence of smoking addiction is nicotine dependence. Once addicted, smokers need to smoke a cigarette every 30-40 minutes to maintain a stable level of nicotine in the brain, and when this level is not reached smokers may feel irritable, sick, nauseous, headache and crave for nicotine refills, feeling as if they are on opiates. Nicotine dependence has all the characteristics of a drug addiction. The causes of tobacco dependence are closely related to the social environment, psychological factors, and genetic factors, all of which are mutually dependent. Only a minority of smokers quit completely the first time they quit, and most smokers experience relapse after quitting and need several attempts to finally quit. Tobacco dependence is a chronic disease, and treatment requires a protracted battle.