【英文摘要】Forest evapotranspiration is major part of forest water balance. It is also animportant representation of forest vegetation growth status. The accurate estimation offorest evapotranspiration is profound to researches of forest hydrologic cycle, watersource reservation and forest productivity. The scope of this program is the typicaltemperate zone Korean-pine and broadleaved mixed forest ecosystem in Changbai Mountainsof China. Based on the estimation of leaf physiological parameters and the synchronousmeasurements of environmental variables, such as atmosphere and soil, models of canopytranspiration, soil evaporation and canopy interception evaporation will be establishedrespectively according to the mechanism of evapotranspiration process. Then a coupledmodel of forest surface evapotranspiration will be established. Model results will becompared with water flux measured with eddy covariance technique. Predictions of theevapotranspiration will be made under different environmental conditions. These resultswill provide theoretical basis of forest water resources assessment and prediction inChina.