Police in the eastern Chinese city of Suzhou detained Gu Yimin on June 1, and later sent a formal statement of arrest, his wife Xu Yan and US-based advocacy group Human Rights in China said.
"He just posted some pictures of June 4 online, and applied to the local government to hold a protest on June 4, he didn't do anything else," she said, referring to the anniversary of the crackdown.
Charges of incitement to state subversion have previously been used to imprison political dissidents.
Gu's lawyer Liu Weiguo said that local police did not allow him to meet with his client when he attempted to visit him at a detention centre last week.
Discussion of the 1989 Tiananmen crackdown, when army troops were sent to crush pro-democracy protests, leading to hundreds of deaths, remain tightly controlled by China's ruling Communist party, which seeks to maintain its grip on power.
