The Heat Balance at Meiji-Shrine Forest, where is one of the largest green area in Tokyo Metropolitan, is observed by botha meteorological (MT) and a plant-physiological (PT) method. 70% of net radiation is distributed to latent heat flux. The diurnal variation of evaporation estimated by MT don't agree qualitatively with that by PT, because the latter is strongly affected by the local meteorological conditions of the sampling site. The characteristics of the stomatal conductance to meteorological conditions can be modeled well by Jarvis equation. The stomatal conductance modified by Jarvis model to exclude the local meteorological conditions, agree very qualitatively with the bulk stomatal conductance estimated by MT.