In recent years, we often encounter parents ask such a question: at the end of every summer vacation, parents are suddenly surprised to find that their children are taller than before the vacation! It is said that spring is the fastest season for children to grow taller, but my child did not see any significant change in spring, but grew a lot taller in summer. Is summer also a good season for children to grow taller? The “Chronicle of the Grand Historian’s Preface” says: “Spring is the season of growth, summer is the season of growth, and autumn is the season of harvest and winter is the season of storage. Summer growth refers to the fact that most organisms grow vigorously and quickly in summer. A report by the World Health Organization shows that the fastest growth rate of children’s height in a year is in May, with an average of 7.3 mm; followed by June to October, with an average of 6.3 mm per month. Therefore, domestic and foreign experts call it the “mysterious May-October”. So, why does the human body grow fastest in May-October? Experts have found that the growth rate of human beings is closely related to nutritional status, geographic climate and physical exercise, in addition to factors such as race, genetics, endocrine and lifestyle habits. Growth itself is a kind of energy, power, is upward, is the scope of Yang, growth needs a lot of Yang, that is, energy, power to encourage, summer is the body Yang and nature Yang are the most vigorous season, is a good season for children’s growth and development can not be missed. From May to October, the sunshine is strong and long, and the infrared rays in the sun have the effect of penetrating objects and heating. The warmth can reach deep inside the body, making the blood vessels of deep tissues expand and the secretion of growth hormone in the body increase, especially promoting the expansion of periosteal blood vessels and accelerating blood circulation, so that bone cells are supplied with more nutrients and bone growth and development will be faster. The ultraviolet rays in sunlight can stimulate the body’s hematopoietic function and increase the number of red blood cells in the blood. More importantly, it also promotes vitamin D synthesis in the skin, which helps the growth of bones. In the survey of youth height in various provinces and cities in China, it is found that the order of youth height is consistent with the order of the length of sunshine in these provinces and cities. It can be seen that there is a close relationship between the growth of bones and the time of light. In addition, during summer vacation, children do not have the pressure of studying, their bodies and minds are fully relaxed, outdoor activities are increased, and they have plenty of sleep time, which are all favorable factors for growing taller. Parents who help their children to seize the summer holidays, it is possible for children who are not ideal height to catch up a big cut. On the contrary, if parents leave their children alone, not only will they not grow sufficiently, but they will develop some bad habits, and the summer vacation will be spent in the monotonous activity of “a remote control + a mouse”.