Natural wetland excluding lake and floodplain in China at present covers an area of around 94,000 km 2 and are mainly located in Qinghai-Tibet Highland (∼50%) and northeast China (∼30%), which can be divided into the peatlands (∼42,000 km 2), freshwater marsh (∼25,000 km 2), swamp (∼2,500 km 2), and salt marsh (∼24,000 km 2). The CH4 flux measured in 2001 and 2002 from the peatland in Qinghai-Tibet Highland and the freshwater marsh in Sanjiang Plain ranged from 0.16 to 10.0 and 1.18 to 54.6 mgCH 4 m −2 h −1 , and averaged 2.96 and 19.6 mgCH 4 m −2 h −1 , respectively. Based on our in situ measurement and the available data measured in the previous studies, the preliminarily estimated budget of CH4 emissions from natural wetlands in China was 1.48 TgCH 4 over the growing season and 1.76 TgCH 4 yr −1 .