Zong is chairman of China's leading beverage producer Wahaha Group and Forbes magazine estimates his personal wealth at $11 billion, second only to Wang Jianlin, head of conglomerate Wanda Group, on $14 billion.
The 67-year old tycoon was attacked on Friday near his home in the eastern city of Hangzhou and injured his fingers, China's official Xinhua news agency said citing police, adding a suspect had been arrested.
Tendons in Zong's left hand were severed, the Shenzhen-based Hong Kong Commercial Daily reported, with a source telling the paper that the attack might have been revenge for the removal of executives at a Wahaha unit.
Representatives of the ruling Communist Party in Hangzhou have become involved in the case, the state-backed agency China News Service reported, citing an unnamed employee at Wahaha.
Neither Wahaha nor police in Hangzhou could immediately be reached for comment by AFP.