Objective   To identify the main problem of family sex education to provide suggestion on how to involve parents well in reproductive health promotion of adolescents and young adults.

  Methods   2 675 youth aged 15-24 years old were investigated with self-administered questionnaire and 20 parents were in-depth interviewed.

  Results   21.97% males and 44.35% females received sex knowledge education from parents, which was focus on hygiene during adolescence.17.36% males and 34.85% females received guidance from parents on how to make friends with peers of opposite sex.Males were less likely to receive sex education from parents, and mother played the more important role in sex education for children.Parents with the higher education level, more rigid discipline for children and the happier environment of the family was more likely to give children sex education.

  Conclusion   Family sex education was far from the satisfactory, which was related with parents' inability and conservative opinion.So it was necessary to strengthen the education for parents to improve their capability and enforce their responsibility of education.Sex education for males should be emphasized.