Gum recession in Chinese medicine is called dental Xuan, Chinese medicine needs to recognize the evidence and treatment. 1. Dental Xuan belongs to the inflammation of stomach fire: gingival recession, accompanied by bad breath, cold drinks, yellow urine, constipation and other symptoms. The formula is to add and subtract Qing Stomach San. 2. Tooth Xuan belongs to the syndrome of deficiency of kidney yin: gingival atrophy, loose teeth, lumbar and knee weakness (the feeling of lumbar and knee weakness), heat in the hands and feet, red tongue with little moss, and fine pulse. The formula is Six-flavored Di Huang Tang plus subtractions. 3. Dental Xuan belongs to the evidence of deficiency of qi and blood: the symptoms include receding gums, pale white color, yellowish face (yellowish color without luster), tiredness and dizziness, pale tongue and weak pulse. The formula is Bazhen Tang plus subtractions. If medication is needed, it should be diagnosed by a doctor and standardized treatment should be prescribed by a doctor.