This book is one of the new generation of youth education series, which is divided into eleven chapters. This paper systematically expounds adolescent changes, adolescent secondary sexual characteristics, adolescent reproductive organs development, adolescent sexual development, conception and contraception, adolescent sexual impulse, adolescent sex education, sexual social problems, sexual crimes, sexually transmitted diseases and prevention, adolescent health and self-care. The book is rich in content, beautiful in language and fluent in writing. It is suitable for teachers, social workers, parents and young friends engaged in youth education.