The issue of Global climate change has recently gained momentum due to its impacts on the environment and its components. Anthropogenic activities like deforestation, agricultural practices, burning of fossil fuels etc. have contributed to the rapid change in the global climate. Disruption of river flows, mobility, dilution of contaminants, effect on chemical reaction kinetics, enhanced potential for toxic algal bloom, reduced dissolved oxygen level, extinction and migration of aquatic animals are some of the implications of climate change. So prediction of climate change for future is of utmost importance to take the necessary measures. Keeping this in view, here we document the future climate change for the Brahmaputra river basin by Global Climate Model (GCM). Temperature and precipitation over the Brahmaputra region was reproduced by two models, namely CSIRO-Mk3.6 and MIROC5. Spatial and temporal resolution of both the models is 4.5km and 1 hour respectively. Rainfall and temperature data for the years 1981-2000 (called the past data) were used as raw data, and used to predict the temperature and precipitation for the years 2046-2065(called the future data). Average yearly temperature for present and future came out to be 280C and 29.50C by CSIRO model and 260C and 27.20C by MIROC model, whereas average yearly precipitation was 1250 mm and 1260mm by CSIRO model and 1300mm and 1300mm by MIRCO model respectively.