The mainland spent more than 400 million yuan (HK$505 million) monitoring pollution in 177 cities last year, according to Wu Xiaoqing, vice-minister for environmental protection.
Cars were the main source of locally generated pollution in the country's four major cities, Wu said on Wednesday at an environmental monitoring site in Wuxi, Jiangsu province.
The ministry had completed analysis of atmospheric pollution in nine major cities, Wu said.
Particles from motor vehicles, industrial production, coal, and dust accounted for 85 to 90 per cent of atmospheric pollution, and cars were the main locally generated source of pollution in Beijing, Hangzhou, Guangzhou, and Shenzhen.
In Shijiazhuang and Nanjing, coal-burning was the primary source of pollution. In Tianjin , Shanghai, and Ningbo, dust, mobile source emissions such as vehicles, and industrial production were the biggest culprits.
Air pollution in the Beijing-Hebei-Tianjin area is notoriously bad, and Hebei, which surrounds Beijing and is China's biggest steel-producing province, accounting for nearly a quarter of the country's steel output.