By using open-path eddy covariance system and meteorological instruments, an observation was conducted on the sensitive heat flux, latent heat flux, net radiation, soil heat flux, air temperature, ground temperature, and precipitation in a intensively managed Lei bamboo forest ecosystem in 2011, with the diurnal and monthly variations of energy flux as well as the distribution pattern of each energy component analyzed, and the Bowen ratio and energy balance closure calculated. The yearly net radiation of the forest ecosystem was 2928. 92 MJ m-2, and the latent heat flux, sensitive heat flux, and soil heat flux were 1384.90, 927.54, and -28.27 MJ m-2, respectively. Both the daily and the monthly variations of the energy components showed a single peak curve. The sensible and latent heat fluxes were 31.7% and 47.3% of the net radiation, respectively, indicating that latent heat flux was the main form of energy loss. The Bowen ratio followed the "U"-shaped pattern, and fluctuated from 0. 285 to 2. 062, suggesting that soil was a heat source. The yearly energy balance closure of the forest ecosystem was 0. 782, and the monthly average was 0.808.