Beijing (CNN) -- China has long been considered a conservative country where talking about sex is taboo, especially to children.
But things have started to change -- slowly.
A report in a local Beijing newspaper about a new sex education textbook for elementary school students -- some as young as six-years old -- has triggered a heated debate in cyberspace and beyond.
The Beijing Times, a popular local tabloid, reported that the textbook, "The Steps of Growth", explains the concept of sexual intercourse with images and illustrations that some people consider too explicit and graphic.
"Is it for elementary school students? That's way too early for them...unacceptable!" one netizen wrote on Sina Weibo, China's equivalent of Twitter.
Some experts in the field even weighed in on the debate. "The content of this text book is not consistent with the children's cognitive capability of this age," said Hu Ping, a sex education expert who owns a studio in Shenzhen, southern China, where she gives classes to young students about sex and health.
"The detailed description of sexual intercourse will trigger the early attention of children about sexual activities," she added.
In contrast, some parents are comfortable with the textbook. "It's better to teach it to the children earlier than later. The kids nowadays know everything anyway," said Li Yan, a father with a seven-year-old son.
Education authorities in China's capital deny the book is a formal textbook to be taught in all the local elementary schools. They say it is only an experiment in some schools.
Nevertheless, in a faxed statement to CNN, they said, "it's very important to carry out health education, including sex education, to elementary and middle school students."
When Li Yan was at school in the 1970s, he recalled the chapter on sex education being skipped entirely by his teachers. According to Hu, this was because sex education in Chinese schools only took off around a decade ago as the country opened up more.
But she concedes the movement has yet to gain sufficient momentum.
She told CNN the main problem with sex education in China is the lack of qualified teachers and textbooks. "The persons who compile the textbooks are not those teach in schools and the schools lack the motivation to develop a sex education system." she said.
However, with higher rates of abortion and increased cases of pre-marriage pregnancy, experts say sex education for young people is becoming more of a necessity.
According to a report by China's National Working Committee on Children and Women under State Council in 2010, 60% of young Chinese aged 15-24 were open to pre-marriage sex, while 22.4% actually had sexual experience.
Among those who got pregnant before marriage, 91% had an abortion, while only 4.4% of unmarried people aged 15-24 had the "correct knowledge" about reproduction. It also added that only 14.4% of that group understood the risks of HIV.
Beijing is not the only Chinese city experimenting with the sex education in elementary schools. In Shanghai, similar experiments are being carried out. According to the state-run China Daily, the first sex education textbook for primary school students will be used in 18 schools in the coming semester.
But the debate remains about the right age for children to receive sex education.
"Children still need sex education when they're little," opined Li Yinhe, a sociologist who specializes in sexology studies in China.
"They need to know basic knowledge such as gender differences. What matters is that the teachers should also tell children what is right and what is wrong in terms of sex morality, and teach the children to protect themselves from sexual assaults."
Beijing has yet to bring sex education into every classroom, but some experts are keen to see it happen as soon as possible.
"An open and appropriate sex education is the best way to help and protect children." Li told CNN.