Five reservoirs located in the Jiangxi Province(Zhelin, Baiyunshan,Doushui, Hongmen and Xiannuhu Reservoirs) were sampled in order to estimate the concentrations of greenhouse gas(GHG) in the surface of these reservoirs. The calculation for diffusive fluxes of nitrous oxide(N_2O), methane(CH_4) and carbon dioxide(CO_2) at the water-air interface indicated that the surface of the reservoirs was a source of N_2O and CH_4 during the sampling period(from 0.29 to 1.05, 3.65 to 39.42 mug/ (m~2·h), respectively). Zhelin Reservoir(-51.56 mug/ (m~2·h)) and Xiannuhu Reservoir(-589.50 mug/ (m~2·h)) surfaces constituted sinks for CO_2. In contrast, the surface of all the other reservoirs were sources of CO_2(from 342.53 to 1383.21 mug/ (m~2·h)). A significant correlation was observed between the magnitude of N2 O diffusive fluxes and the TN. Water temperature, transparency and TP should affect the CH_4 fluxes. There was no relationship between the CO_2 emission and other environmental factors. Taking into account the global warming potential of N_2O and CH_4, the total fluxs of CO_2 equivalents (TF_(eq)-CO_2) was estimated that ranged from 237.83-2267.83 mug CO_2-e/ (m~2·h).The contribution of N_2O, CH_4 and CO_2 to TF_(eq)-CO_2 range from 13.94% to 83.26%, 20.54% to 175.21% and from -140.43% to 60.99%, respectively.The contribution of N_2O to TF_(eq)-CO_2 were similar to that of CH_4 in all reservoirs. For Zhelin and Xiannuhu Reservoirs, the contribution of CO_2 to TF_(eq)-CO_2 was negative, but it was the most significant in the other reservoirs. The TF_(eq)-CO_2 from each reservoir were equivalent to the 10.52-377.10 t C/ a of the carbon emissiom that were much lower than the annual CO_2 emissions from themal power plants burning coal(from 0.05% to 1.12%).