In the lower atmospheric planetary boundary layer, turbulent transport is an important connection for substance and energy exchange between the atmosphere and earth's surface. Currently it is a focus of earth system science. As a part of the ChinaFlux program, the components of energy balance fluxes were measured continuously over an oak(Quercus aliena) natural forest at a transitional climatic zone in Central China since 2009. Using an open-path eddy covariance system and micro-climate instruments, the net radiation, sensitive heat flux, latent heat flux, soil heat flux, air temperature, soil temperature, and precipitation were measured in the oak forest in Henan Province from October 2016 to September 2017. The diurnal and monthly variation of energy balance, as well as the distribution pattern of each component were analyzed, and the energy closure and Bowen ratio were also calculated. As an important index to evaluate the reliability of eddy covariance measurements, energy balance analysis has been widely accepted by the FLUXNET community. Using the ordinary least squares (OLR) method, energy balance characteristics of the oak forest were systematically analyzed. The results showed that the annual net radiation of the forest ecosystem was 2626.17 MJ/m², and the latent heat flux, sensitive heat flux, and soil heat flux were 1417.25 MJ/m², 867.1 MJ/m², and -2.60 MJ/m², respectively, suggesting that soil was a heat source. The energy balance components had obvious seasonal variations, whereas diurnal variations of energy balance components showed a single peak curve. In the dormant season, the turbulent energy exchange was dominated by an upward sensible heat flux, accounting for 54.2% of the available energy; whereas in the growth season, turbulent energy exchange was dominated by an upward latent heat flux, accounting for 67% of the available energy. The annual rainfall in the study area was slightly higher than the average (1231.8 mm); compared with 579 mm of evapotranspiration at the same time period, the results showed that only 47% of precipitation was returned to the atmosphere through evapotranspiration. The Bowen ratio was more affected by the forest phenology, with an average value of about 2.1 and 0.2 in the dormant and growing season, respectively. Soil heat flux during the growth season was positive, suggesting that soil was a heat sink, whereas it was a heat source during the dormant season. The process of soil heat exchange was mainly controlled by the net radiation, whereas the phenology of the forest also plays a role. Energy balance closure is regarded as a standard, evaluating the reliability of the eddy covariance measurement at FLUXNET sites. Energy balance closure in the Baotianman station was 67% on a half hourly basis, which fell in the range of the most FLUXNET sites (55%-99%), indicating that the flux data was basically reliable. Energy imbalance may result from the complex land surface, sampling mismatch between the flux footprint and sensors measuring other components of energy balance, negligence on the canopy heat storage, etc.