Abstract. Accurate assessment of water budgets is important to water resources management and sustainable development in catchments. Here the VIP (Vegetation Interface Processes) ecohydrological model is used to estimate the water budget and its influence factors in Hutuo River basin, China. The model runs from 1956 to 2010 with a spatial resolution of 1 km, utilizing remotely sensed LAI data of MODIS. During the study period the canopy transpiration takes up 58% of evapotranspiration over the whole catchment and the fractions of soil and interception evaporation are 36% and 6% respectively. The annual evapotranspiration and streamflow are both declining, mainly resulting from the decrease of annual precipitation. Attribution analysis shows that the contributions of climate change and human activities to the decrease of streamflow are 48% and 52%, respectively.