Boys height fierce long period that is the peak period, generally divided into infancy and puberty two stages, rather than three stages. 1. Infancy: the average length of 50cm at birth, the fastest growth in length in the first year after birth, about 25cm; the first three months of growth in length of about 11 to 13cm, about equal to the value of growth in the last nine months, the length of about 75cm at the age of one. 2. puberty: puberty is the transition period from childhood to adulthood, boys about 11 to 13 years old, height began to accelerate the growth of 1 to 2 years after the growth of the second peak, at this time, the average annual increase in height of boys 9 to 10 cm. in the second growth peak, the increase in height is about 15% of the final height. It should be noted that due to the individual’s physical condition and the time of development, the peak of height growth may also vary from person to person. If your height is abnormal or you experience discomfort during your height change, you should seek medical attention.