To evaluate the impact of global warming on tree phenology, components of leaf phenology in 29 broad-leaved tree species in the warm temperate zone were observed for 7-10 years. The Cumulative Temperature (CT) method was used to predict the late stage of bud unfolding and mean leaf-fall date. For the late stage of bud unfolding, the prediction error for the indirect estimation approach, which adds the estimated leaf expansion period to the budburst date, was smaller than the direct estimation error using the CT method. For the mean leaf-fall dates, the estimation revealed significant effects in 7 of 15 deciduous broad-leaved species. The impact of global warming (1 to 4℃ uniform warming) on leaf phenology was simulated. For each ℃ of warming, the budburst date was accelerated by 3.4 d in evergreens and deciduous trees, the mean leaf-fall date was delayed 6.2 d (deciduous trees), and the photosynthetic period was prolonged by 10 d (deciduous trees).