Yang Peiquan, 49, set fire to himself at about 7:45 a.m., Xinhua said. It said police put out the flames and that Yang suffered only unspecified minor injuries. It said he came from the central province of Hubei.
The incident came as China celebrated the 54th anniversary of the founding of its communist government, an event that draws thousands of people to the square. Xinhua didn't say how many people were nearby at the time of the fire.
It was the second time in two weeks that a Chinese man set himself on fire in the square.
On Sept. 17, a man who state media said was protesting the demolition of his home in the eastern province of Anhui poured gasoline over himself and set himself ablaze on the square. He was reportedly hospitalized with minor burns.
In January 2001, five people set themselves on fire on Tiananmen Square in an incident that Chinese authorities blamed on the banned Falun Gong spiritual movement. Two of the people - a woman and her 12-year-old daughter - were killed.