Girls in a province in southwest China are being given tips on how to say no to boys asking for sex.

Girls in Yunnan province are being given a booklet that teaches about chastity. The Yunnan provincial education department has asked all local high schools and universities to 'teach girls how to reject sexual requests until marriage', the Global Times reported citing the Chuncheng Evening News.

Authorities have introduced a textbook on sex education titled 'Focus on the Family' published by a US-based Christian organisation.

The booklet covers a wide range of topics, including the human reproductive system and how to prevent AIDS.

Yang Gonghe, a director of the provincial education department, said sex and life education would be introduced in other provinces also.

According to data collected from over 80,000 college students from across the country, 14 percent admitted to having sexual relations during their college days and about 70 percent held a tolerant attitude toward sex before marriage, the Nanjing Morning Post reported.

Yang Wanqiu, a professor at the counselling centre at Yunnan University, said it was important for girls to refuse sex during college and before marriage.

'If a girl had sex with her boyfriend, she would become mentally dependent on the boy,' Yang said. 'It would do no good for her studies and daily life.'

Meanwhile, Xu Tao, a student at Yunnan University, said for want of sex education, most university students learn about sex from pornography.

In Xu's opinion, if the man and woman are truly in love and intend to marry each other, sex before marriage is acceptable.

Nie Wen, 21, said she did not think sex before marriage should be forbidden. 'Both my boyfriend and I are over 18, and we are already adults,' Nie said. 'We had been in love for three years, and sex has improved our relationship.'