It said China's environmental situation was "extremely grim".
The big cities are smothered in eye-searing smog. China has some of the world's strictest emissions standards, but authorities have refrained from enforcing them until now to avoid forcing older, pollution-belching trucks off the road and hurting small businesses.
The new announcement suggests authorities have settled that conflict in favour of environmental protection after reports on the health and economic costs of pollution.
Plans call for retiring five million older, polluting vehicles in Beijing, the nearby port of Tianjin around Shanghai, and around the southern business centre of Guangzhou, according to the statement.
The statement gave no details on the remaining one million vehicles to be taken off the road.
China has about 240 million vehicles, about half of them passenger cars, according to the Ministry of Public Security.
It is the world's biggest car market by number of vehicles sold. Sales rose 15.7 per cent last year to 17.9 million vehicles.
Taxi fleets and public buses in major cities have been required to switch to cleaner-burning natural gas or battery power. The Government is promoting development of an electric car manufacturing industry.
Beijing, Shanghai and other large cities have imposed curbs on new vehicles in an attempt to reduce smog and traffic congestion.
With New Zealand's average car 14 years old, do you think we should be getting rid of polluting clunkers? Tell us at facebook.com/DrivenNZ