Second-hand smoke on the newborn’s respiratory system, nervous system and all organs of the body have certain damage, affecting the growth and development of newborns. 1. Respiratory system: tar, nicotine and hydrocyanic acid and other chemical substances in tobacco have a variety of damaging effects, such as damage to the airway epithelial cells and cilia movement, so that the airway purification ability to decline; prompted by the bronchial mucous glands and cup-shaped cell hyperplasia and hypertrophy, mucus secretion increased; stimulate the parasympathetic nervous system so that the bronchial smooth muscle contraction, airway resistance increased. All these damages will affect the normal respiratory function. 2. Nervous system: nicotine in tobacco stimulates the sympathetic nerves, and long-term exposure of babies to the stimulation of neurological excitatory substances will have an impact on the development of the nervous system. 3. All organs of the body: toxic and harmful substances in smoke may reach various tissues and organs of the body through blood circulation, such as the heart, liver, kidneys, etc., and cause certain damage to these tissues and organs. There are many other hazards of secondhand smoke such as increased risk of cancer, affecting blood oxygen saturation and other unhealthy for themselves and their children, it is recommended that parents must quit smoking.