The law goes one step further than a new set of anti-corruption and ethics laws released by the central government on Sunday, which include banning government officials from using their influence to benefit their lovers.
The new law in Guangdong, also known as the Canton Province, is part of a set of laws on women's rights. The legislation forbids married men from setting up "love nests" for their mistresses, and is aimed at "preserving and enhancing marital stability," the Beijing News quoted Guangdong lawmaker Cheng Jingchu as saying.
The practice of Chinese businessmen setting up second homes for their lovers has become widespread in the country in recent decades.
Xinhua News Agency said the central government regulations, consisting of 55 articles set to come into force on June 1, also threaten demotion or dismissal for state officials who inflict damage on the environment, provoke mass protests, visit prostitutes, take drugs, or organize "superstitious gatherings."
The agency quoted Deputy Minister of Supervision Qu Wanxiang as saying the new regulations would help the ruling Communist Party to "safeguard state power, improve ethical standards of officials and persuade them to adopt a clean, honest and down-to-earth work style to better serve the people."