The purpose of the study was to understand the spatial variability of climate change impact in Blue Nile Basin based on hypothetical climate change scenario and using HBV hydrological model. The assessment samples were 10 catchments of the basin. And hypothetical climate change scenario that range between (-30 to +30) for both precipitation and PET have been investigated. In terms of evaluation of water resource change, most of the stations exhibit more than 18% increase in runoff for PET decrease of 30% Meanwhile most of the stations exhibit more than 50% increase in runoff for rainfall increase of 30%. On contrary, 30% reduction in rainfall showed slightly reduced percentage reduction in runoff than the increased rainfall produced. These sensitivity analysis conducted on watersheds and river basins under a variety of scenarios may help policy makers to prioritize measures and /or understanding the effects of climate change for planning and, management water resources within the Blue Nile Basin.