Zheng Shouquan of the Qing Dynasty, in his “True Tradition of Medical Science”, gave a clever play to the meaning and application of the formula for both Fengmingdan and Qianyangdan, arguing that both formulas have the method of returning qi to the kidney and drawing fire back to the yuan. The former formula consists of three herbs, namely Huang Bai, Sha Ren and Gan Cao, focusing on diarrhea. The latter formula is composed of four medicines, namely Sharen, Radix et Rhizoma, Tortoise, and Licorice, focusing on tonification. The author used the two together to treat persistent oral ulcers with satisfactory results, which are described below. Yang, female, 68 years old, was seen on February 26, 2012 for “sores in the mouth and tongue with recurrent pain for more than 4 years”. The patient had mouth sores 4 years ago, which improved when treated with internal Chinese and Western medicines, but worsened in the past 2 years and was treated by Chinese and Western doctors with no significant effect. The symptoms include: pain in the mouth and tongue, irritability, fear of cold drinks, hot and spicy stimuli, dry throat, thirst, dry cough at night, thin stools without odor and stickiness, urine, poor sleep, no sweating and weakness, and multiple ulcers on the palate and tongue surface. He has a moderate form, with a yellowish complexion, a light red tongue, thin white fur, a sunken pulse and a slightly stringent left guan. Differentiation: deficiency of kidney yang and deficiency fire on inflammation. Herbs: Huang Bai 30g, Sha Ren 15g, Sheng Gan Cao 30g, Radix et Rhizoma Polygonati 15g, Sheng Bai Shao 25g, Sheng Long Bone 30g, Sheng Oyster 30g, Sheng Bai Zhu 25g, Di Yu Char 10g, Bai He 10g, Lian Lian 3g. 6 doses, decoction in water, 1 dose daily. On the return visit on April 2, the disease was cured, no recurrence was seen, diet and sleep improved significantly, and weight increased. Note: As stated in Nei Jing, all pains and sores belong to fire. This is a case of inflammation due to deficiency fire. “The tongue is the seedling of the heart”, so the deficiency fire burns the mouth and tongue, hence the sores. This formula is modeled after Zheng Qin’an’s recipe for Qian Yang Dan, which Zheng called “the method of returning Qi to the kidney”. Zheng pointed out that “Yang is strong to be able to shock the group of yin, yin begins to descend, Yang begins to be hidden”. The author believes that Phellodendron can clear the heat and strengthen the yin, and that it can be used with Radix et Rhizoma Phellodendron and Radix et Rhizoma Sibiricum without defeating the stomach and cutting off the yang. The pungent warmth of the sand is able to declare all the yin and evil in the middle palace, and it can return the qi to the kidneys, leading the essence of the five viscera and six internal organs to the kidneys; the pungent hotness of the sophora can supplement the true yang in the kan, the true yang is the seed of the ruler’s fire, and supplementing the true fire is to strengthen the ruler’s fire; the combination of peony and licorice is peony licorice soup, which was renamed A-Hi-Hua-Tu Tang by Tang Rongchuan in the Qing Dynasty, taking peony acid belongs to A wood, and licorice sweet and slow belongs to He-Tu, “A-Hi-Hua-Tu “It is said to be “long muscle” and “cure the wind between the skin and hair”. The Tangliu Materia Medica says that it is “in the qi main qi, in the blood main blood”. The author believes that the oral cavity is usually impregnated with water-dampness, the patient drinks a lot and is thirsty, and the water-liquid is not functioning properly. The use of keel bone and oyster instead of tortoise shell to submerge the yang into the yin, but also to revive the tranquilizer; ground elm char, white and cool the blood, stop bleeding, astringent sores and muscle. The “holy medicine for sores” is forsythia, which clears heat and astringes sores. The combination of all the drugs can play the role of submerging the true fire, inducing fire to return to the source, clearing heat and astringing sores, so that the long-suffering mouth ulcers are healed.