Haikou, capital of China's southernmost Hainan province, was found to be the cleanest city of China in 2012, according to the Annual Report on Environment Development of China (2013) released on April 11. This is the 5th year of Haikou ranked No.1 on the list.

Chen Chao, director of the Environmental Protection Bureau of Haikou said Haikou's government attached great importance to environmental protection work and has invested 5.12 billion yuan (US$ 827 million) to protect the environment during the previous Five-Year Plan (2006 - 2010).

According to daily air quality figures of major cities released by the Ministry of Environment, the report listed 31 cities and municipals air quality index, including the days with Grade 1 (excellent air quality) and Grade 2 level (good), days with sulfur dioxide, days with nitrogen dioxide and the days with inhalable air particles.

The report was published by Friends of Nature, the oldest environmental NGO in China. It has published the annual environment report of China for eight consecutive years.

Also read:Top 10 most polluted Chinese cities in 2012

The following are the top 10 cleanest Chinese cities in 2012:

  Chongqing

Rank in 2012:10

Rank in 2011:16

Rank in 2010:20

Rank in 2009:24

Rank in 2008:24