A professor of literature, Liu took part in the 1989 pro-democracy movement and was a leading negotiator between the Tian'anmen Square protesters and the government. He was imprisoned for 21 months as a result. After calling for the release of other Tian'anmen demonstrators who were still being held in 1996, he was again arrested and served three years in a labor camp.
Liu was one of the authors and advocates of Charter 08, a document published in 2008 advocating human rights, political freedoms, and free elections in China. The document was modeled on Charter 77, a similar set of demands by Czechoslovak citizens in 1977. After its publication, Liu was arrrested, and in 2009 he was found guilty of "inciting subversion of state power" and sentenced to 11 years in prison, in what Amnesty International has called an unfair trial.