Li died of an unspecified illness in Beijing on Monday night, the state-run Xinhua news agency reported Tuesday. State media listed him as 91 using the Chinese method of counting age. He would have been 90 in the Western calendar.
During the pro-democracy movement that swept China in the spring of 1989, Li was the face of hardline leaders who refused to negotiate with the protesters and sided with then-paramount leader Deng Xiaoping in ordering the military crackdown.
It was Li who, as Premier, declared martial law in Beijing on national television on May 20, 1989, paving the way for the Tiananmen Square massacre two weeks later, in which hundreds of people were killed.
Despite his controversial image, Li remained unchallenged as China's number two leader through the 1990s and into the early 2000s, second only to then-President Jiang Zemin, as the ruling Communist Party tried to present a united front.
His preference for state control over market forces in running the economy, however, reportedly led to him losing influence as Premier to his lieutenant Zhu Rongji, handpicked by Deng to resurrect stalled economic reforms and market liberalization.