Adverts will not be allowed in the middle of programmes lasting for 45 minutes from 1 January next year.
The authorities said this was in line with the “spirit” of a recent Communist Party meeting.
Senior leaders said then that they wanted to develop a “socialist culture”, although they did not elaborate on exactly what that means.
TV stations are clear about what this latest move means for them though – they say it could result in a loss of revenue.
The latest announcement was made by China’s State Administration of Radio, Film and Television (SARFT) on its website.
It said the regulation was being introduced as part of a new attitude towards culture, outlined at the party’s Central Committee meeting in October.
“Radio and television are a mouthpiece of the party and the people – an important propaganda front in cultural thought,” read the SARFT statement.
An organisation spokesman told Xinhua, the state-run news agency, that the aim was to make TV shows conform to “public interests and aspirations”.
The Communist Party has always kept close control over cultural activities such as television programming.
A few months ago it told a successful commercial station to stop broadcasting a popular talent contest called Super Girl.
A spokeswoman for Hunan Satellite TV said this new regulation came after most advertising deals for next year had already been signed.
China’s TV advertising industry was worth nearly 500bn ($78bn, £50bn) yuan last year.