Study on the impact of climate change on hydrological cycle in river basins has received much attention worldwide.Mathematical statistics and hydrological modeling are widely used for impact assessment. A summary of the impact of climate change on hydrological cycle in river basins is presented in five key aspects: trend analysis of hydro-meteorological factors,performance assessment on General Circulation Models (GCMs),selection of downscaling technique,selection of hydrological model and uncertainty analysis.The Lhasa River,the biggest tributary of the Yarlung Zangbo River,has been selected for the case.It has been found that future runoff exhibited much more spatio-temporal heterogeneity due to significant increase of runoff during flood seasons and significant decrease in dry seasons;this will be a great challenge for flood control and drought relief in the study area.Systematic explanation and in-depth understanding of how climate change affects hydrological cycle in river basins,and associated key issues on impact assessment are of great importance for future water resources management.