The two rival Palestinian factions have failed to heal their political disputes since Hamas fighters expelled Fatah from Gaza in a short war in 2007
The Shenyang legal bureau said in a brief statement on its website that Liu had suffered multiple organ failure and efforts to save him had failed.
Liu, 61, was jailed for 11 years in 2009 for "inciting subversion of state power" after he helped write a petition known as "Charter 08" calling for sweeping political reforms.
He was recently moved from jail to a hospital in Shenyang.