When Ren Yi began teaching Chinese in the US city of Denver over 20 years ago, she never thought she would become a popular author of Chinese language textbooks.

"My self-made Chinese textbooks have been sold through Amazon and other sales channels, so far the feedback is very positive," says Ren.

Standing in a booth at the recent annual convention of the Chinese School Association in the United States in St. Louis, Missouri, Ren greets the attendees.

"There is increasing demand for my textbooks from US teachers of the Chinese language and students who want to improve their skills," Ren says, adding that the publishing house of her books has asked her to write new editions.

Ren graduated from Tsinghua University, a top Chinese university. She started to write a book for beginners with the encouragement of her students, who told her that her lectures were more educational than classroom texts.

"I tried to develop the first edition of Chinese language books for American students, which turned out to be a big success," Ren says.

She spent three years writing her first book and soon started to write the second. She says she improves her books based on daily teaching experiences.

In the past 20 years, Chinese education has witnessed tremendous momentum in North America, thanks to dedicated educators, CSAUS president Liu Shen says. In recent years, Chinese language education in the US has entered a new era.

"More than 200 students have been studying Chinese in our school in the last two or three years, which is three times more than we predicted. Most of them go for our innovative teaching of Chinese traditional culture like lion dancing, Peking Opera and so on," says Xiao Teng, principal of Ames Chinese Language Academy in the US state of Iowa.

"We find more and more Americans are learning Chinese in Iowa," adds Xiao.

Founded in 1994, the CSAUS is a non-profit composed of over 500 Chinese schools in over 50 US cities, with over 100,000 students and over 8,000 teachers.