The causes of cough variant asthma are intricate. Among them, family history of allergy and personal history of allergy are risk factors for cough variant asthma, and infection, environment, food, medicine, emotion and exercise are important reasons for triggering or aggravating the development of cough variant asthma. When both parents are allergic, 70% of their children can acquire allergic constitution; if the mother alone is allergic, her children have 50% chance of inheritance; if the mother alone is allergic, her children have 30% chance of inheritance; but there are also allergic constitution within the range of brothers, sisters, grandparents, uncles and parents, cousins However, allergies can also be found in brothers, sisters, grandparents, uncles and cousins. Xing Xianghui, Department of Pediatrics, Affiliated Hospital of Shandong University of Traditional Chinese Medicine 2. Personal allergy history: such as allergic rhinitis, eczema, seborrheic dermatitis, etc. 3, respiratory tract infection: virus, Mycoplasma pneumoniae infection as the main factors. 4.Environment: dust mites, dust, pollen, toy lint, animal dander, cockroaches, haze, decoration materials, passive smoking, etc. 5, food: seafood, animal protein, raw, cold and sweet food. 6.Drugs: such as misuse of heat-clearing and bitter-cold products and heavy use of antibiotics, etc. 7, strong emotional changes. 8.Exercise and hyperventilation.