Irrigation is significant in increasing agriculture production and productivity for sustainability of country's economy. Impacts on existing activities for irrigation design and management system is obvious due to rapid change of climate system. This paper future focus to evaluate the influence of changing climate on the crop yield and irrigation requirement for Wonji Shoa Sugarcane Plantation Estate. For future climate data, it used the results of projections of cordex regional climate model (RCM) with bias correction for medium concentration representative path way 4.5RCP and high concentration representative path way 8.5RCP scenario. The down-scaled data were then used as input to the AQUACROP model. The time series indicate a significant increasing trend in maximum and minimum temperature values and a slight increasing trend in precipitation for both 4.5rcp and 8.5 rcp scenarios. The evapotranspiration shows an increases in 20.34%, 20.12%, 23.59% and 24.36% for 8.5 rcp in the period of 2020s, 2040s, 2060s, 2080s respectively. For 4.5rcp scenario the change is in about 8.4%, 11.65%, 13.22%, and 15.85% for the period of 2020s, 2040s, 2060s, and 2080s respectively. The model output shows that there is an annual increase in yield. For 8.5 rcp scenarios, the incensement is 6.2%, 7.84, 11.03% and 14.48% in 2020s, 2040s, 2060s and 2080s respectively. For 4.5 rcp scenarios the increment is much lower compared to 8.5rcp scenarios. But there is steel increasing in yield for 4.5rcp. The change is 0.3%, 1.8%, 7.02%, and 4.82% for the period of 2020s, 2040s, 2060s, and 2080s respectively.