Vitamin K is an old hemostatic drug. In recent years, this class of drugs has been found to have many pharmacological effects. For example, it can directly release the smooth muscle of the gastrointestinal tract and bronchial smooth muscle spasm, antagonize the excitatory effect of acetylcholine and pentoxifylline on smooth muscle, so it has the effect of analgesia, antidiarrhea and asthma; it can also delay the degradation of adrenocorticotropic hormone in the liver, and has the effect similar to hydrocortisone; at the same time, it can inhibit the growth of intestinal bacteria, and has the effect of antibiotics. It is especially effective, convenient and economical to treat many pediatric diseases, and its adverse effects have not been detected. Treatment of capillary bronchitis – This disease occurs mostly in infants and children from 6 months to 2 years old, with wheezing as the main clinical feature. Traditional asthma control generally uses adrenocorticotropic hormones, aminophylline and promethazine, but the efficacy is poor and the effect is slow. The application of vitamin K3, 2 mg per kg each time under 1 year old and 1 mg per kg of body weight each time over 1 year old, twice a day; for light wheezing, intramuscular injection; for severe condition, adding 10% glucose 100 ml to static drip, can achieve satisfactory antiasthmatic effect. Treatment of pediatric asthma persistent state – sudden onset of pediatric bronchial asthma manifested as wheezing and paroxysmal dyspnea. Severe asthma attacks with symptoms lasting more than 24 hours develop into asthma persistence. Apply vitamin K3 1 mg per kg of body weight each time, add 10% glucose 20 ml and push it quietly, the symptoms will be relieved soon. Treatment of whooping cough – Whooping cough is a common acute intestinal infectious disease in children, characterized by spasmodic cough, and there are no effective drugs for cough control so far. Intramuscular injection of vitamin K1 has a 92% cough suppression efficiency. Specific use: less than 6 months 10 mg; 6 months to 2 years 20 mg, 2 to 5 years 30 mg, more than 5 years 50 mg, once daily. Treatment of infant diarrhea – for the treatment of pediatric diarrhea, the clinical use of oral or intramuscular injection of antibiotics, slow efficacy and poor antidiarrheal effect. Jiangsu Jianhu County near Lake Hospital in the past two years, the application of vitamin K3 treatment of infant diarrhea 100 cases, the efficiency of 93%, of which 71 cases with the drug 8 hours after the disappearance of symptoms, the number of stools and the nature of improvement.