The characteristics of land surface/air energy translation was analysed on the basis of the observation data collected over a maize field in the North China Plain. The results indicated that the energy balance processes of land surface were greatly affected by the features of underlying face. Latent heat fluxes were the main component of land surface/air energy exchanges. Daily sensible heat fluxes were turned to be negative in the late growth period of maize. Among factors regulating surface energy translation, bulk canopy resistance was seasonally changed with high values in the early and late stage and with low value in the mid stage, and the lowest value of 25 s.m-1. This trend was closely related to soil cover fraction and leaf senescence condition. Water use efficiency (WUE) was not changed with evapotranspiration. The low WUE in the early stage means that the energy resources were not fully utilised, and the high WUE in the late stage means that enough soil water content was the key for high and stable yield.