TV stations could face a reprimand or the loss of their commercial broadcast rights if they air any advertising during the 45-minute episodes, the State Administration of Radio, Film and Television said in a statement on its website.
The rule is meant to "lift the standards of public cultural services" and "protect the people's basic cultural rights," the regulator said. It also designated January as a "special month" for enforcing the ban throughout the country.
China's Communist Party has been pushing to assert more influence over the nation's culture and society, including in television and the arts. After a meeting in October, the Party's Central Committee released a communique vowing to "promote more fine literary and artistic works" in fields such as TV, movies and photography.
At the same time, the media regulator unveiled new limits on the number of "overly entertaining and vulgar" reality and talent shows aired on TV. The communique also said the government would strengthen management of online social media sites on which users have criticized the government and exposed official graft.
The media regulator had earlier ordered Hunan Television to suspend broadcasts of its "Super Girl" singing competition, similar to "American Idol," for infractions including the exceeding of limits on the length of the shows, the official Xinhua News Agency reported.