Some parents often ask how to evaluate their child’s growth and development and ask if their child is normal. First of all, it should be clear that pediatric growth and development includes two major parts, one is physical development and the other is neuropsychological development (commonly known as intellectual development), and when both are normal development can be called a healthy child. Physical development includes weight, length, head circumference, chest circumference and nearly 10 other items. Among them, weight and length are important indicators. Weight is the most sensitive indicator to observe the physical development of children, so every parent should always weigh their children. But what is the practical significance of weight for children? How can it be evaluated? Not many people really know. Body weight is the total weight of the body organs, tissues and fluids. It is a timely reflection of the child’s recent nutritional status and disease. Therefore, it is important to weigh the child regularly. In general, it is best to measure children within 6 months of age once a month, every 3 months from 6 months to 1 year, every 6 months above 1 year, and once a year above 3 years. It is best to use a lever scale to measure weight, check the zero point before measurement, take off the child’s coat, shoes and hat, and try to empty the urine for older children, so that the weighed value is more accurate. Normal newborns are born weighing more than 2500 grams, if less than 2500 grams for low birth weight babies, if equal to or more than 4000 grams for huge babies. Just born newborns due to more sleep and less food, breathing, skin evaporation and urine and stool discharge lead to weight loss, this situation is medically known as physiological weight loss, in the 3-4 days after birth weight loss nadir, generally not more than 7%-8% of the weight at birth, and then gradually increase, 25-30 grams per day growth Afterwards, the weight loss will gradually increase by 25-30 grams per day and return to the birth weight in 7-10 days. At full term, the weight should increase by 600-800 grams. The first year after birth is the period of fastest weight gain. For example, a child with a birth weight of 3 kg will weigh twice as much as at birth at 3 months, about 6 kg, 3 times as much as at birth at 1 year, about 9 kg, and 4 times as much at 2 years. after 2 years of age, the average growth is 2 kg per year. Length (height) is measured from the top of the child’s head to the bottom of the foot. 3 years old and younger are measured in a lying position, so they are called length; after 3 years old, they are measured in an upright position. The length of children under 3 years of age is closely related to nutrition and disease, and after 3 years of age, height is more obviously influenced by race, genetics and environment. The relationship between height and short-term nutritional changes is not obvious, but there is a relationship with long-term nutritional status. Length also grows fastest in the first year of life. For example, a child’s length at birth is 50 cm, and it grows by about 25 cm in one year; at age 1, it is about 75 cm, and it grows by about 10 cm in the second year, and increases by an average of 5-7 cm per year until adolescence. Regular growth in weight and length is a sign of good health. When a child’s weight and length do not grow regularly, it means that he or she may be fed improperly, overfat when there may be excess nutrition, slow growth or no growth may be due to poor food quality or diseases (such as pneumonia, diarrhea and other diseases) affecting the development of the child’s physique, and measures should be taken to actively find the cause. Note; to measure height, we should pay attention to the same time and place, the same measuring device, otherwise there will be errors, generally there is a difference of 1 to 2 cm in the height of children in the morning and evening.