For boys, the main criterion for puberty is the maturation of the sexual organs, including the testicles and scrotum, as well as the appearance of the beard, throat nodes, and the change of voice. Generally speaking, the testicles and scrotum usually start to grow between the ages of 10 and 13, and the earliest appearance is pubic hair, while pubic hair usually appears between the ages of 12 and 13, and axillary hair appears about a year later than pubic hair. In addition, the beard appears a little later, usually around the age of 15. Another sign of maturity in boys is seminal emission, the average age of first seminal emission is 14 years old. There is also a change in the voice and the appearance of the laryngeal nodes. After the laryngeal nodes are raised, the voice changes, usually around the age of 14. Therefore, for male characteristics, beard, protruding laryngeal nodes and voice change are obvious signs. If the above mentioned characteristics are over a certain age, you should go to the hospital for further examination if they never appear.