Guo Quan, who was released Wednesday, is the first known case of someone being detained for quake-related criticism. Other detentions reported by state media have been of people accused of spreading rumors of future quakes.
The criticism came as China enjoyed rare praise for the relative openness of its earthquake response and media coverage of the disaster, which has killed more than 68,000 people.
The articles by Guo said the Chinese government ignored warning signs before the May 12 quake, and that officials should have immediately responded to the danger of lakes formed by the quake that now threaten to burst. He also questioned the safety of nuclear facilities in the area.
At least one of his articles was published by The Epoch Times, a U.S.-based newspaper linked to the banned Chinese sect Falun Gong.
Guo has already been in trouble with police for founding the China New Democracy Party last year and claiming it had 10 million members in China and overseas. He also gained headlines earlier this year by threatening to sue Yahoo and Google in the U.S., accusing them of blocking his name from search results in China.
Guo, reached by phone Thursday in the central city of Nanjing, said police told him his detention was mainly for his quake-related articles.
"I'm used to this kind of thing," Guo, 48, said of the police treatment. He and his wife, Li Jing, said his computer was seized but later returned.
Calls to the media office of the Public Security Bureau in Nanjing rang answered Thursday.
Guo, an expert on Chinese literature, lost his teaching duties at Nanjing Normal University after founding the China New Democracy Party.
While in detention, police told him to give them the list of the party's members and other party documents. Guo said he refused.
"We're not against the Communist Party," he said. "We just want people to have the right to choose a party."