The first Affiliated Hospital of Henan College of Traditional Chinese Medicine, Department of Pediatrics, Yan Yongbin (The first Affiliated Hospital of Henan College of Traditional Chinese Medicine, Yan Yongbin) “Su Wen – the four times of Yin and Yang, the root of all things. So the sage spring and summer nourish Yang, autumn and winter nourish Yin, from its roots, so with all things floating in the door of growth.” “The method of nourishing the yang in spring and summer, and nourishing the yin in autumn and winter, which is in accordance with the changes of yin and yang in the four seasons, has been valued by medical practitioners for generations, and has long been an important guide for people to maintain health and prevent diseases, and to resist old age and prolong life. However, there are many ambiguities in the understanding of this sentence, from its literal meaning, that is, in the spring and summer seasons, it is appropriate to maintain Yang Qi, and in the autumn and winter seasons, it is appropriate to maintain Yin Qi. The author combined with the clinical, just on the meaning of this sentence to talk a little bit of their own experience. The understanding of this phrase has been inconsistent among commentators throughout the ages. Tang Wang Bing believes that in spring, Yang is strong and easy to hurt Yin, so it is advisable to eat cold and suppress its Yang hyperactivity, while in autumn and winter, Yin is strong and Yang is insufficient, so it is advisable to eat warm and complete its true Yang. However, Zhang Zhicong of the Qing Dynasty believes that in spring and summer, Yang is strong outside but deficient inside, so it is advisable to nourish the Yang that is deficient inside, and it is advisable to use hot and pungent food to “nourish Yang”; in autumn and winter, Yin is strong outside but deficient inside, so it is advisable to nourish the Yin that is deficient inside, and it is advisable to use cold and nourishing food to “nourish Yin”. In contrast, Gao Shizong believes that we should follow the different characteristics of the four seasons to nourish our health, such as nourishing Yang in spring and summer, so that the Qi of Shaoyang will be born and the Qi of the Sun will grow; nourishing Yin in autumn and winter, so that the Qi of Taiyin will be collected and the Qi of Shaoyin will be hidden. The above three commentaries are understood according to the coherence of the scriptures, but the statements are not the same, and some are obviously contradictory, making it difficult for post-graduate students to follow. The author has a different understanding here, and believes that “nourish” means to adjust, conform, maintain, and reserve, and its fundamental purpose is to ensure that Yang Qi grows and collects in accordance with the times. In spring and summer, Yang Qi is active, the climate is warm and hot, and the couples of the organism are open, consuming more Yang Qi. In addition, the natural air humidity increases due to the transpiration of Yang Qi, and moisture is a yin evil, which is easy to hurt Yang Qi in the human body; in addition, it is easy to lose Yang by drinking cold, resulting in Yang Qi depletion. At this time, we need to nourish yang because of its “internal deficiency”; the cold climate in autumn and winter, yin qi is in charge, the muscle surface is dense, yang qi does not easily leak out, resulting in yang qi is strong and yin qi is weak. And the natural Yang collection, inhibit the ground moisture transpiration, the air dryness heavy, dry is Yang evil, the action on the human body is most likely to hurt Yin liquid. In addition, the autumn and winter like to eat spicy and warm products, more wantonly eat paste beam thick taste, resulting in internal heat, every easy to consume yin to help Yang, so at this time to because of its “Yin Qi internal deficiency and nourish Yin”. This is the so-called “internal deficiency and nourishment”. “Nourishing Yang in spring and summer, nourishing Yin in autumn and winter” is a proactive principle of health care, the essence of disease prevention and treatment. The author believes that the basic meaning is to change the way of living according to the change of seasons, to adjust the mental state, and to comply with the changing laws of yin and yang in the four seasons. Su Wen – Four Qi Tuning Shen Da Lun said “The four seasons of yin and Yang, the fundamental of all things.” The changing laws of the four seasons of yin and yang directly affect the prosperity, life and death of all things. “Nourishing Yang in spring and summer, and nourishing Yin in autumn and winter” is the essence of Chinese medicine in preventing and treating diseases. The principle of treatment according to the time of the year can be divided into winter and winter treatment for winter diseases. Patients with yang deficiency and yin hyperactivity physique, who develop or worsen in autumn and winter, often receive good results by adopting the treatment of winter illness and summer health. For patients with yin deficiency and yang hyperactivity, every spring and summer onset or aggravation, take the method of summer disease and winter treatment, at this time to nourish yin with the help of the weather and get twice the result with half the effort. In conclusion, “nourishing yang in spring and summer, nourishing yin in autumn and winter” is the guiding ideology of Chinese medicine for health care and disease prevention and treatment, and its view of nourishing health in accordance with the time, treating according to the time, and choosing the time to prevent disease is the model of Chinese medicine time medicine, which reflects the holistic concept of “heaven and man correspond to each other”. It has important clinical and practical significance.