Greenhouse gases (GHG) represent two atmosphere gaseous components, natural and made via human activities which cause the global warming phenomena. Climate change and global warming are imposing additional pressures, with negative effects on the quantity and quality of water resources and the capability to ensure food security, protect human health and preserve ecosystems. The present study focuses on responses the characteristics of precipitation due to climate changes over the greater zab river (GZR) basin at Eski-Kalak gauging station (20435 km2) during the observed period (1979-2005), near (2047-2073) and distant (2074-2100) future periods under both emission scenarios the medium (RCP4.5) and the high (RCP8.5). The regional climate model RCA4 by using Coordinated Regional Climate Downscaling Experiment (CORDEX) program has been utilized to obtain the predictions of precipitation within Middle East North Africa (MENA) region. The results indicated that an increasing in rainy days and intensity of daily precipitation for prediction periods compared to the observed period. Daily analysis over the projection periods indicate that likely to be occurred extreme precipitation on the basin reach to 120 and 132 mm under medium and high emission scenarios, respectively whereas, during the observed period the maximum daily precipitation was 73 mm. The increasing of average annually of total precipitation as a ratio to the observed period were 23% and 28% under scenario RCP4.5 whereas, under high scenario RCP8.5 were 25% and 23% for mid and end 21st century periods, respectively. According to a higher frequency and intensity of precipitation, the GZR basin would be experienced flood events in future.