Chinese Cinnamon is the dried bark and branch bark of Cinnamomum camphora, which is usually selected between August and October, and the bark is peeled according to a certain breadth and processed into different specifications. It is mainly cultivated in sandy soil and sloping mountainous areas. It is mainly produced in Guangxi, Guangdong, Yunnan and other places. Taste is pungent, sweet and hot. Mainly enters the kidney, spleen and bladder meridians. Functions: Tonifying the vital energy, warming the spleen and stomach, removing accumulated cold, and promoting blood circulation. It is used for treating failure of the vital gate fire, cold limbs and weak pulse, deficiency of the dead Yang, abdominal pain and diarrhea, cold hernia, cold pain in the waist and knees, menorrhagia and obstruction, gangrene, flowing injection and deficiency of Yang floating over, upper heat and lower cold. Usage: It is mainly used internally, in decoction, pills, and powder, or externally, in powdered form or in wine. Contraindications: mainly contraindicated for yin deficiency and fire heat, and caution for pregnant women. Modern clinical application: It is very useful in the treatment of bronchial asthma.