The move comes as part of a campaign by President Xi Jinping to show that the ruling Communist Party (CPC) is cracking down on corruption and waste.
Glitzy new government buildings, sometimes in impoverished areas, have been a source of public outrage.
The directive forbids luxury makeovers and expansions done under the guise of repair work, Xinhua news agency said.
The notice says some departments and local authorities have built huge government office compounds against regulations, tainting the image of the CPC.
Among the buildings that have attracted widespread disapproval in recent years is the western-style government office building in the city of Fuyang in Anhui province, in eastern China.
It reportedly cost 30 million yuan ($4.89m, Â£3.19m) to build and is referred to as the 'White House' by residents.
A state-owned drug company also caused outrage after photographs emerged apparently showing a building decorated to mimic France's Versailles palace, complete with gold-tinted walls and chandeliers.
Some government agencies have reportedly built luxury offices in seaside resorts where officials can stay for free or at deeply discounted prices.
The ban - described as an "across-the-board halt" - includes training centres, hotels or government motels, Xinhua said.
It also says government organisations should not receive sponsorship or donations towards construction projects, or collaborate with private companies.
"Banning the building of new government buildings is important for building a clean government and also a requirement for boosting CPC-people ties and maintaining the image of the CPC and the government," Xinhua quoted the directive as saying.
Tackling corruption has been President Xi Jinping's most high-profile policy since he became China's leader earlier this year.
He has warned that "corruption and bribe-taking by some party members and cadres" pose "severe challenges" to the Communist Party's rule.

The Fawlty Towers and Monty Python star was quoted in a magazine interview last year as saying "there's no way I want to work in TV, especially at the BBC".
In recent years, the 74-year-old British actor has mainly concentrated on voiceover roles.
But BBC comedy head Shane Allen told the Daily Telegraph Cleese is a "comedy god, and the door is always open".
"We're in discussions about a piece that he might be in. It's a sitcom and it's very early days," Mr Allen said.
Cleese, who appeared on the big screen in A Fish Called Wanda and two Harry Potter films, did take on small appearances in US TV sitcoms Whitney and Entourage between 2010 and 2013.
He also reunited with his Monty Python co-stars in 2013 for live shows to pay an Â£800,000 legal bill after losing a royalties case. And following his divorce from third wife Alyce Eichelberger in 2008, he performed in a comedy show dubbed the Alimony Tour.
In last year's interview with Shortlist magazine, Cleese said he felt the BBC's commissioning editors had "no idea" what they were doing.
He also said he had been offered "cliched" roles by ITV.
Referring to Cleese's possible BBC sitcom return, Mr Allen told the Telegraph: "There are certain people who have earned their badges, who have got the right to do what they want."
He was speaking to the Telegraph before the first episode airs on Sunday in the BBC's "landmark sitcom series".
The series features modern remakes of Are You Being Served?, Porridge, Till Death Us Do Part,  Steptoe and Son, and Up Pompeii!
Mr Allen said it was "insulting" to suggest the BBC's new comedies were not as good as the past but added: "This is a chance to try to reclaim that and say these are titles and writers and pieces of work that are proven, and hallowed, and it's a chance to introduce them to a new generation."
A BBC spokeswoman said: "We would love to work with John Cleese. However nothing is confirmed at this stage and we do not comment on developments."
China has banned the construction of government buildings for five years, according to state media.
[NEXT_CONCEPT]
John Cleese is reported to be in talks to return to the BBC for a sitcom which has been written specifically for him.