The height and weight of infants at different stages are not growing at an equal rate and there is no uniform standard, which can be assessed according to the formula. Infant height standard, the average length at birth is 50cm, the fastest growth in the first year of life, can reach 25cm, especially the first 3 months of growth of about 11~13cm, equivalent to the growth value of the last 9 months, until the age of 1 year, the length of about 75cm; 2~12 years of age, the height (cm) formula for: age x 7 + 75. The standard of infant weight, the birth weight is about 3.25kg, 3~12 months after birth weight (kg) formula: (age + 9) รท 2, the first 3 months of the infant’s weight increase value, is equivalent to the latter 9 months increase value; 1~12 years of age weight (kg) formula: age x2 + 8. There is no uniform standard for the height and weight of infants at different stages, which can be judged on the basis of the change in height and weight of the child.