The source area of the Yangtze River (YR) originates from the Tibetan Plateau,where regional climate warming has been observed over the past half century,leading to growing spatial heterogeneity of hydrological processes in the area. However, researches on the variation of hydrological processes were restricted due to insufficient observations. In this study,the hydrological processes in the source area of YR were investigated using hydrological modeling and integrated multiple observations. Using historical data from 1979 to 2012, the hydrological processes of three major sub-basins (i. e.,Tuotuo River (TR),Qumar River (QR) and Dam River (DR)) were analyzed by the Cold Region Hydrological Model (CRHM). Then, the spatial-temporal characteristics of the processes and their hydrological responses to climate change were analyzed in different hydrological response units (HRUs). According to the results, the average runoff depth and average runoff coefficient were 56.4 mm and 0.2 in TR,7.1 mm and 0.03 in QR and 152.0 mm and 0.41 in DR sub-basins,respectively. The spatial distribution of the runoff depth and runoff coefficient in each sub-basin as well as the whole region varied distinctly with a decreasing trend from south to north. This phenomena demonstrated a moderate agreement to the spatial variation of precipitation over the region (correlation coefficients R > 0.54,and statistical significance p <0.01),which revealed the influence of precipitation to hydrological processes in this region. The sensitivity of the modeled hydrological processes in different altitudes was also illustrated by the simulation; runoff depth of the mountain area in the southwest was significantly higher than one in the lowlands,showing high positive correlation against precipitation (R > 0.95, p < 0.01). In the swamp dominating southeast area,however,much lower runoff depth was obtained due to high evapotranspiration. This study suggested that hydrological responses to climate changes in the source area of YR were strongly related to the spatial heterogeneity in different sub-basins,which should be carefully taken into account in estimating further hydrological variations in this region.