In true precocious puberty, the secondary sexual characteristics of both boys and girls appear before the normal age of puberty (earlier than 8 years old for girls and 9 years old for boys), but the procedure is similar to that of normal development. The clinical manifestations of girls are firstly breast development, with nucleus formation and local elevation into a small mound, while the nipple and areola gradually increase in size. At the middle stage of breast development, pigmentation of the areola and nipple appears. At the same time, since the early stage of breast development, the growth rate is accelerated, and the growth peak of puberty is also advanced, the subcutaneous fat increases significantly, and the height and weight often exceed those of children of the same age. Most of the pubic hairs appear about one year after breast development, while the axillary hairs appear even later, often after menarche. The internal and external genitalia are enlarged, there is pigmentation of the labia minora, and white vaginal discharge appears. The age of menarche is early and menstruation with ovulation may occur. The above developmental process is continuous and progressive until the final sexual maturity and fertility is achieved, but the speed of the process varies from person to person. Rapidly progressive true precocious puberty in both men and women, the bone age often significantly exceeds the actual age, and thus the epiphysis matures too quickly and heals early, which will eventually affect the lifelong height of adults. Enlarged testicles are the first important feature of true precocious puberty in males, followed by penile growth, enlarged scrotum, increased scrotal skin folds, deepened pigmentation, pubic hair growth, increased penile erection, seminal emission and even sperm growth. The order of appearance of male secondary sexual characteristics such as axillary hair, beard, throat nodes and voice change is also similar to that of normal pubescent children, only at an earlier age. In the middle stage of testicular development, the growth rate of the child is accelerated, but the increased bone maturation also leads to premature healing of the epiphysis. Children with true precocious puberty, both male and female, have physical and sexual characteristics similar to those of older children with normal puberty, but their intellectual development level is still consistent with their actual age. Early bone age only indicates that the level of sex hormones has been increased for a period of time and is not a specific indicator for the diagnosis of cPP. Precocious puberty has a huge impact on children’s physical and mental health, so it is important to seek medical attention as soon as you find out that your child is developing early now. Out-of-town patients can communicate with me by phone before the consultation about precautions and registration to avoid a wasted trip.