Men generally mature sexually when they are about 15 years old. The exact time cannot be generalized, but needs to be judged in the context of the actual living environment of the male and other factors. Sexual maturity generally refers to the stage when the individual already has reproductive function and the development of sexual organs reaches its peak, with basically no obvious changes. The male population usually starts their first sexual development between the ages of 10 and 13, at which time the penis, testicles and other sex organs will enter a rapid growth period, and men will first experience skin folds on the penis and other parts of the body, pigmentation, pubic hair growth and other conditions, accompanied by a protruding knot in the throat, etc. The testicles will then enlarge in about a year. Afterwards, testicular enlargement, thickening and growth of the penis will occur in about one year, and androgen levels in the body will also rise significantly. Generally around the age of 15, the length and size of the penis and testicles will be developed to the peak, and then begin to develop slowly, basically no obvious changes, and at this time the semen already contains active sperm, and has the ability to procreate. Some men also experience frequent erections and spermatozoa, which usually indicates that their sexual development has matured. However, due to the large individual differences between different men, some men with better living conditions and higher nutrient intake usually have earlier sexual maturity, so the exact time cannot be generalized. To summarize, in general, when a man has the ability to bear children, he is considered to have matured sexually in clinical practice. If a man is about 15 years old and still does not have active sperm in his semen, he should be alerted to precocious puberty, etc. It is recommended that he go to the hospital in time for examination and follow the doctor’s instructions for treatment.