Wang, forced to wear a necklace of ping-pong balls when she was purged at the height of the Cultural Revolution, died of heart and kidney failure at a Beijing military hospital on Friday, Taiwan's United Daily News reported.
Jia Qinglin, ranked fourth in the Communist Party hierarchy, will attend her funeral at Babaoshan Revolutionary Cemetery in western Beijing on Friday, Hong Kong's Beijing-funded Wen Wei Po said.
She had been married to Liu Shaoqi, who replaced Mao Tse-Tung as China's president in 1959.
Chinese state media have not reported her death, apparently to avoid rekindling unwanted memories of her bitter experiences during the Cultural Revolution, which Mao unleashed to get back at Liu and other political rivals for taking away his day-to-day running of the country.
China has barred media reporting and commemorations to mark the 40th anniversary of the start and 30th anniversary of the end of the Cultural Revolution this year.
Wang reportedly incurred the wrath of Mao's wife, Jiang Qing, for wearing a pearl necklace at a time when fashion, make-up and women's accessories were considered bourgeois decadence.
She was forced by Red Guards to wear a necklace of ping-pong balls when she was purged in 1967. She was then jailed for 12 years.
Her husband Liu replaced Mao as president in 1959 on grounds that the chairman's 1958 Great Leap Forward campaign to overtake Britain's economy was a disaster and led to a man-made famine which eventually killed about 30 million people.
After her release from prison, Wang dedicated her life to poverty alleviation.
She was nominated last month for the 2nd China Poverty Eradication Awards.