Abstarct: Water management has become a management crisis for countries in the recent century, in particular for the poor countries, due to increasing population, food supply and climate change. One way to reduce water consumption is to employ the optimal cultivation pattern. For this purpose, this study aimed to determine the optimal cultivation pattern under climate change scenarios in Shahroud region using genetic algorithm. To determine the optimal cultivation pattern, MATLAB program was used. In this study, the area under cultivation of each crop was considered as a variable of decision and minimizing water consumption and maximizing farmer's profit were considered as the objective function. Then,13 scenarios were defined in the Genetic Algorithm program. The area under cultivation of each crop changes in each scenario so that in the first scenario from zero to one hundred percent of the area under cultivation in the region, in scenarios 2 to 10, from 10 to 90% of the current area under cultivation of each crop and in scenarios 11 to 13 from 10, 20 and 30% of the total area under cultivation are subject to change. Regarding climate change, temperature and precipitation of 25 AOGCM models were determined under two scenarios of RCP4.5 and RCP8.5 in the next two periods of 2010 to 2039 and 2040 to 2069. Then, evaporation and transpiration of the two scenarios under 25%, 50% and 75% risk were calculated and the optimal cropping pattern program was implemented again in these 12 cases. The results reveals that in determining the optimal cultivation pattern in the current situation, scenario number 12 is the best scenario. This scenario shows a 7% reduction in water consumption and a 122% increase in profit. This scenario allocates the highest area under cultivation to wheat and barley and the lowest area under cultivation to alfalfa and melon. The results of combining climate change conditions with genetic algorithm for Scenario 12 indicate that under climate change conditions, the area under cultivation should be reduced by 20%. The results show that in the scenarios of RCP4.5 and RCP8.5 in both periods, after wheat, the trend of changes in the area under cultivation is almost the same in all scenarios. In all climate change scenarios, onion has the highest area under cultivation and beetroot has the lowest one.