Xu Lai, who writes under the pseudonym Qian Liexian, was attacked Saturday evening at the Wanda branch of the Beijing Danxiangjie Book Store, a staffer there confirmed Monday.
He was meeting readers "and it happened after that," said the clerk, who declined to give her name as is common among Chinese. She gave no other details.
Xu, who is also culture editor at the Beijing News paper, was apparently stabbed in the store's bathroom by two men who later fled, according to friends and fellow bloggers who posted the news online.
The motive was unclear for the assault, which was the first known physical attack on a prominent blogger.
Xu's blog, entitled "Qian Liexian Wants to Speak," offers witty, satirical observations on society and politics. At times provocative, he has also commented on government corruption and the recent scandal of milk contaminated with an industrial chemical.
Last year, he was listed among the "20 Most Influential Figures in China's Cyberspace" by Southern Metropolis Weekly. Xu was in a Beijing hospital Monday recovering after surgery for his wounds, which were not life-threatening, according to postings by friends on the bullogger.com Web site.
"According to the doctor, there was only a small hole in his stomach, and no other injuries were found in his other organs," one post said. "The doctor said it seemed that he was in a good condition. So people who care for him should not worry."
Police responsible for that area of Beijing did not immediately respond to requests for comment.
Xu's blog was one of many hosted on the Chinese blogging Web site bullog.cn, which was shut down in January as part of a government crackdown on the Internet. The successor site, bullogger.com, is hosted overseas.
Online writers and commentators in China are often censored and sometimes persecuted by authorities over controversial postings.