China's cities of Sanya and Haikou, both in south China's island Hainan Province, have been listed among the top ten cities with best air quality in the world.

A UN environmental organization has surveyed nearly 160 key cities worldwide.

Sanya is in the second place, while Haikou stays in the 5th place.

The other three cities among the top five are Havana in Cuba, Mendoza in Argentina and Tampere in Finland.

Edited by taiwan.cn online member Li Guixiang.