China will no longer treat death tolls in natural disasters as a state secret, the Xinhua news agency reports.
Death tolls from typhoons and landslides have been kept secret
The move is a bid to make government more transparent, a spokesman for the official body for state secrets said.
The declassification of such figures would help disaster prevention and relief work, he added.
Death tolls from natural disasters have been closely guarded secrets in China for decades. Unauthorised attempts to obtain figures have led to jail terms.
Casualty numbers from typhoons and earthquakes have usually been released through official channels such as Xinhua or government agencies.
Shen Yongshe, spokesman for the National Administration for the Protection of State Secrets, said China had decided to "declassify" such information last month.
He said the move would "ensure the people's right to know" but gave few details of what it would cover.
Foreign journalists were not invited to the news conference in Beijing, underscoring the political sensitivity of the issue.
Ching Cheong has been charged with passing information to Taiwan
Although information has become more readily available in recent years, China has a track record of imposing news blackouts on accidents and disasters.
It remains unclear whether Beijing will start retroactively revising death tolls from such events as the famine in the late 1950s and early 1960s, in which millions of people are believed to have died.
Human rights groups have previously accused the authorities of using hazily-defined laws on state secrets as a means to silence journalists and critics.
Reporter Shi Tao was jailed for 10 years in April for "divulging state secrets", after he sent overseas an e-mail citing a Communist Party circular on media restrictions.
Hong Kong journalist Ching Cheong was last month charged with buying information to pass to China's rival Taiwan - and could face the death penalty if convicted of spying.
Jiang Yanyong, a Chinese doctor who exposed Beijing's cover-up of the extent of the 2003 Sars outbreak, was later arrested after writing a letter denouncing the 1989 Tiananmen Square crackdown.