Abstract: A winter wheat farmland ecological system located at the Feng-Qiu agricultural ecological experimental station of the Chinese academy of sciences in the Huanghuaihai (Huanghe,Huaihe,and Haihe rivers) plain was selected as the test object in this paper.Using the data observed by the eddy covariance system and the automatic meteorological stations from October 2013 to June 2014,the energy balance at each growth stage of the typical winter wheat in the Huanghuaihai plain was analyzed based on eddy correlation and correlation analysis methods.The main purpose of this study is to find the relationships between each flux and the environment meteorological factors in the farmland.The results show that the energy partitioning feature at each growth stage is different for the winter wheat.The percentage of latent heat to the net radiation at the seedling period is only 40%,while for the periods of jointing and heading,it is more than 80%,and for the other periods,it is also more than 55%.The percentage of sensible heat to the net radiation decreases with growth,reaching 50% at the sowing and seedling periods,and below 35% at tillering and the following periods,until jointing and heading periods with only 10%.During the whole growth period,the percentage of soil heat flux to the net radiation is stable,with 15% overwintering period and less than 10% at the other periods.The energy closed degree is high,with 83% at the seedling period,90% at the tillering period,and more than 90% after returning green period.There is a positive correlation between air temperature and each flux,and a negative correlation between relative humidity and each flux.The correlation coefficient between soil temperature and soil heat flux is about 0.5.There are no significant correlations between soil temperature and net radiation,latent and sensible heat fluxes.The correlation coefficients of soil water content with each flux at sowing and returning green periods are 0.5,and for the other growth stages,this kind of significant correlation is not found.