Hong Kong adolescents have become increasingly more liberal in sexual attitudes. However, their sexual knowledge remains unsatisfactory, which might lead them to engage in risky sexual behaviour or early sex debut. The Hong Kong AIDS Foundation revealed that in 2018 among the 536 respondents completed a questionnaire, 52 reported that their first sex was at age 15 or below, and five were at age 11. The Family Planning Association of Hong Kong indicated that in 2021, among the 33 secondary school students who experienced sexual intercourse, 20 had it at age 13 or below. Early sex debut is of great concern because it has found to be associated with poor physical health, psychological problems, social maladjustment, and even suicidal thoughts.

Another sexual health problem is the experience of child sexual abuse (CSA), which results in long-term psychological distress and social maladjustment. Many CSA survivors suffer from depression that deleteriously affects their quality of life.

To protect the sexual health of adolescents and children, sexuality education should start early so that they learn to protect themselves from CSA and sexual harassment. It helps them to avoid undesirable sexual activities in adolescence. Sexuality education in primary school involves not only providing sexual knowledge and fostering positive sexual attitude, but also developing children's healthy self-concepts and self-confidence in taking charge of their lives and to be responsible for themselves and others.

The World Health Organization (2010) considers a child to be a sexual being from birth. In recent years, with increasing social and economic growth, improvement of nutrition and health status, the start of puberty can be expected at age 8 to 9. To protect sexual health of children, sexuality education needs to begin early.

Teachers play a very crucial role in the implementation of sexuality education in primary school. If they are not supportive, feel uncomfortable in teaching sexuality topics, or judge that the sexuality topics are unimportant, they would be unwilling to engage in teaching sexuality. Teachers' sexual attitudes, sexual knowledge, religiosity, and sociodemographic characteristics are important factors that need to be investigated for effective implementation of sexuality education in primary schools.

Existing evidence indicates that parents also need to be involved in sexuality education. Parental teaching at home provides an extended environment affecting students' learning of sexual knowledge and positive sexual attitudes. Empirical literature showed that mothers have greater self-efficacy about sexual communication with children. They placed greater importance on topics covered in sexuality education than fathers and they felt more comfortable discussing sexuality topics with children. Furthermore, children tend to initiate communication of sexuality with mothers more than with fathers. To limit our sample to a minimal, we focus our study on the role of mothers. Data gathered from mothers would be compared and integrated with those on teachers who engage in school-based sexuality education. 

Adopting a method of cluster random sampling, 12 primary schools from Hong Kong Island, Kowloon, New territory East and West are invited to participate in the study. Through school principals agreeing to participate, 250 teachers and 250 mothers of school children at primary 1 to primary 6 are invited to fill in a questionnaire containing items related to teaching sexuality in school and in family. Participation is voluntary and anonymous. Informed consents are solicited before the commencement of the questionnaires survey.

Results of the study would present evidence-based information on factors associated with teaching sexuality. Data on teachers and mothers would be integrated. Through seeking common ground while retaining uniqueness, teachers and mothers would work together to protect and promote sexual health of school children in Hong Kong.