In this study, the possible effects of climate change on the minimum, maximum and precipitation values of Karun catchment were investigated. The output data of HadGEM2-ES model under RCPs scenarios were micro-scaled by LARS-WG6 and the future perspective of temperature and precipitation changes during the three periods 2021-2040, 2041-2060 and 2061-2080 compared to the base period was examined. According to the results, In all three future periods and under all three emission patterns, the minimum and maximum temperature anomalies are positive in all seasons; In the distant future and under the RCP8.5 scenario, the maximum anomalies of minimum and maximum temperatures are predicted to be 4.2 in summer and 4.8 ᵒC in spring, respectively. The seasonal average of the basin shows that the highest amount of rainfall decrease in the distant future period, under RCP4.5 scenario, in winter is equal to 55.1 mm and the greatest increase in rainfall in the near future, under the RCP8.5 scenario, will occur in the fall at 21.6 mm. During the period 2021-2080, the long-term average annual rainfall will decrease between 1.9 to 14.6% in future periods compared to the base period. The average annual temperature rises between a minimum of 1.2 to 3.4 and a maximum of between 1.3 and 3.7 ᵒC. Analysis of the spatial distribution of temperature and precipitation variables in the basin in future periods indicates that the territory of rainy and cold regions will be more limited and the area of low rainfall and warm regions will be increased.