Now Yang's tales sell in the millions, with some translated into Korean, French and English; and although the writer shrugs off the comparison, she is often described as the J.K. Rowling of China. Last year, she was the top-selling author on Amazon's China website, nudging out fellow children's author Shen Shixi and even Nobel laureate Mo Yan.

The lucrative mainland children's book market has raised a few eyebrows in literary circles in recent years.

Children's book publishing has grown at double-digit rates each year since 2000, and the trend is is likely to continue for the next decade, Hai Fei, director of the Children's Literature Publication Working Committee in China, has told last year. Annual sales have also grown to about 6 billion yuan (HK$7.4 billion).

For publishers, the boom in children's books helps to make up for sagging sales in other genres. But critics often dismiss authors such as Yang as lowbrow attempts to cash in on families' focus on their children's learning.

"Nowadays, not many adults in China read books, but almost every child is doing some reading. Unlike their parents, these schoolchildren often read the same books recommended by teachers. Parents are all keen to spend money on books for their kids," An Wulin, a children's writer from Shandong province, told the provincial .

Zhu Ziqiang, head of the Children's Literature Institute at Ocean University in Qingdao and a writer of children's tales, has long been a critic of Yang's stories. "Reading her books is like watching television programmes. Though entertaining, they are shallow and do not involve much thinking," he wrote in 2007.

Yang, 51, a former teacher from Sichuan province, earned an estimated 20 million yuan from book royalties last year alone. However, she insists she has never seen writing as an easy path.

"All my life I have done nothing but work and write for children," she says at her posh apartment in central Beijing. "To write well for children, you need to really understand them."

Yang grew up in Chengdu and became a Chinese language teacher at a local primary school after she completed training at the age of 18. After her first year on the job, she began writing stories to supplement her pupils' meagre reading material.

"It was in the early 1980s, not long after the Cultural Revolution. The kids were bored with the textbooks and there was not much good material to choose from outside class," she says.

Her first story, , was a lesson about propagation wrapped in a fanciful tale about a lotus seed floating about in a pond in its leathery green suit.

"All children like good stories. I felt that introducing some simple science under the guise of a good story might appeal to the class," she says.

Yang had modelled her story on a popular children's tale about a tadpole's search for its mother, and was anxious about how it would be received by her class. So she slipped it inside another book before reading it to them.

"In this way, I get instant feedback from them, and that's how I know exactly what appeals to children," she says.

Their enthusiastic reaction gave her the confidence to write more. By the time her first primary students reached Year Six, she had written more than 100 stories.

She developed a bigger following when a Shanghai children's newspaper began publishing her tales, and a book contract followed.

"Unlike other writers who struggled with many returned manuscripts, I was lucky that my writings were accepted from the start. Every single word that I have written so far has been published," she says.

When her first class graduated from primary school, she also left teaching to become a children's book editor for a publishing house.

In the early 1990s she joined a children's magazine as editor-in-chief, where she was primarily responsible for writing a series of short stories about a fun-loving boy, Mo Xiaotiao, who often gets into trouble with his teacher and class monitor.

Yet Yang remained largely unknown outside the circle of children's writers until 2000, when the Beijing-based Writers' Publishing House released her which sold two million copies. Its success brought her almost instant fame. Set in the final year of primary school and inspired by her own daughter, is an intimate portrayal of a girl on the cusp of adolescence.

became one of her most popular works, with the 20 titles in the series so far selling 30 million copies.

But her most successful may turn out to be with the 18 titles in the series having sold 20 million copies. Launched in 2006 for children aged between seven and nine, it chronicles the adventures of a talking pet cat and features characters from .

It is difficult to come up with fresh material in such long-running series, but Yang believes she has not disappointed her publisher or readers yet.

Surprisingly, she didn't read much as a child. That changed in her teens, when she developed a fascination with Chinese classics such as and , and repeatedly read episodes.

"The plots and intricate relationships were beyond my understanding [at the time] but I studied how the author introduced each character," she says. "This later helped my writing, and that's probably why each of my characters stays in the mind of the reader."

Children's fiction is such a profitable business that publishing houses are clamouring for more material, and this has prompted many mainland writers to switch genres. But books by Yang and her fellow children's authors often get short shrift from more educated parents.

Li Sipan, director of an online women's group in Guangzhou, says she would not pick Yang's books for her daughter, 12, though she would not necessarily ban them.

"Nowadays everything in China is geared towards maximising profits. I prefer her to read imported books from the West. We cannot physically move to the West, but we can expose her to books with a different ideology," Li says.

"It's a pity that China is home to Confucius and other great thinkers, but we do not have books for children that are as good as the series by French philosopher Oscar Brenifier [on the 'art of thinking']."

In Beijing, Jiang Hongmei generally steers her two young daughters away from the new generation of children's writers. On the drive to school, Jiang says, they usually listen to stories about Chinese history or audio books written by Western masters.

"We recently finished by Italian novelist Edmondo De Amicis. All three of us were so touched by the story," she says. "Recent Chinese books are like fast food and we don't have time for them."

Wang Gan, a Yale-educated anthropologist now running a preschool in Beijing, is put off by what she sees as the mediocre characterisation and literary quality of Yang's stories. Yet her son loves the simple tales, so Wang instead encourages him to read a variety of other authors.

"When the children read more, they can establish a sense of judgment," Wang says. "Children's authors in China are way behind their Western counterparts. We need time to catch up."