The latest statistics from the State Forestry Administration shows that wetland in south China's Hainan island covers 320,000 hectares.
A book on China's wetland resources, published on Sunday, said there are 242,000 hectares of natural wetland in Hainan while the other 78,000 hectares are artificial.
Jiang Haisheng, chief editor of the book, said most of Hainan's wetland are in the eastern and northern part of the island.
The wetland in Hainan is important to the island's eco-system. Wetland can help with pollution degradation, climate regulation and preservation of the local biodiversity, according to Jiang.