The CO₂ and CH₄ fluxes on wetland (water level drawdown) area of reservoirs are crucial parts of the scientific research of reservoir Green House Gas emission.CO₂ and CH₄ fluxes at soil-water interface of Baijiaxi and Yanglu drawdown areas in the Pengxi River were studied from June to September in 2010.Baijiaxi drawdown area has a mean CO₂ flux of 12.38±2.42 mmol/ (m²·h),while its mean CH₄ flux is 0.0112±0.0064 mmol/(m²·h).The mean fluxes of CO₂ and CH₄ at soil-air interface in Yanglu drawdown area are 10.54±5.17 mmol/(m²·h) and 0.14±0.16 mmol/(m²·h),respectively.A significant increase of CO₂ flux and a comparable decrease of CH₄ during the study period have been observed.Recovery of the vegetation and an increase in soil organic matter contents are generally regarded as the primary reason for the increase of CO₂ flux.Loss of water in soils during the period increases the intensities of oxygen transfer from air to soils,which could help to increase the activities of methanotrophic bacteria,and to increase the capability of CH₄ sink in the drawdown zone.However,it is suggested that further study should be taken on elucidating the co-effect of CO₂ and CH₄ fluxes by the reservoir operation and land-use history in this area.