The New York Times reports the new rules come at a time when hundreds of millions of people in China get information from microblogs.
The new rules ban reporters from directly including unverified information from the Internet or mobile phone messages in news articles.
The rules, announced on the Web site of the General Administration of Press and Publications, also require journalists to have at least two sources for "critical" news reports.
The government also says corrections and apologies must be issued after false reports and that serious violations could lead to suspension or revocation o a news outlet's license, issued by the government.
"False reports not only seriously hurt the interests of the parties involved, but also seriously undermine the credibility of the news media, or even seriously affect the social and economic order," the agency said in an article released by the state news agency Xinhua.
The Times said Chinese authorities were especially worried about rumors of corruption or abuse of authority by government officials. Such rumors, which spread quickly, are a frequent topic on microblogs.