Kindergarten children are to receive sex education lessons in a two-year pilot project.
Formal sex education is now only available to secondary pupils - aged 12 and over. There are no lessons on the subject in primary schools, although some individual schools teach it outside the curriculum.
The project, sponsored by the Education Department, will offer a school-based sex education training programme for teachers and parents at 25 kindergartens or nursery schools.
A teaching kit based on four topics - the body, the role of sex, the origin of birth and child sexual abuse - has been developed.
The Family Planning Association of Hong Kong launched the Early Childhood Sexuality Education Development Project after receiving $250,000 from the department's Quality Education Fund.
The association's chairwoman, Dr Susan Fan Yun-sun, said children as young as two or three began to show curiosity about sexual matters. 'They touch their own sex organs, which is very typical,' she said.
Dr Fan said if children received sex education earlier, their anxieties could be relieved. 'It will then set a better foundation for them to learn sex education in primary and secondary schools, to let them develop a correct attitude towards sex in an era flooded with sex information.'