The development of the male child’s reproductive system actually begins at 6-7 years of age with varying degrees of development, with the prostate gland developing a little later, usually after 12 years of age, and the seminal vesicle glands synchronizing their development after 12 years of age. However, testicular and penile development is often seen at 7-8 years of age when a child can see significant changes in the reproductive system. Many children actually begin to show a series of more typical secondary sex characteristic changes such as growing pubic hair and longer pubic periods before they enter puberty. So don’t be nervous about the corresponding changes in the reproductive system at this age, many of which are normal. However, children who are too young to develop these secondary sexual characteristics prematurely, such as 4-5 year olds, should be alerted and must be taken to the hospital to be examined for adrenal tumors, which are a very common problem. There are also some children whose reproductive system develops particularly late, at the age of 16-18 even pubic hair does not grow, the length of the penis is not big, or an undeveloped state of the shape of the penis. In such cases, it is also necessary to go to the hospital in time to check the level of sex hormones, to find out the cause of the lack of sex hormones, and if necessary, we not only need to treat the cause of the disease, but also to give some androgen supplementation to stimulate the development of secondary sexual characteristics.