Agriculture remains the main source of food and income for most rural communities in Ethiopia. Understanding the impact of climate change on crop production can help to optimize schemes and increase yields. The main aim of this study was, therefore, to modeling climate change and its impacts on food barley (horduem vulgare l.) production using different climate change scenarios in Lemu Bilbilo district, Oromia regional state, Ethiopia. Time series anomaly for temperature showed that both annual maximum and minimum temperature have increased by 0.06 oC and 0.11 oC respectively and rainfall showed slight variability during the period of 1980-2010.The projected temperature and rainfall pattern shows that an overall increasing trend in annual temperature and significant variation of monthly and seasonal rainfall from the historical period of time. Days to flowering, maturity and yield of HB1307 variety simulated by DSSAT V4.6 model was calibrated and evaluated by Root Mean Square Error (RMSE), Index of agreement (IA) and coefficient of determination (R2). Therefore, RMSE, IA and R2 revealed a very nice agreement with observed data's set. The Results indicate that food barley yield decreases on average by 22%, 24% in 2030s RCP4.5 and RCP8.5 respectively. Similarly yield decreases on average by RCP4.5 (25%) and RCP8.5 (19%) in 2050s relative to the baseline (1980-2009) due to climate change. Early sowing should be considered as an adaptation strategy for food barley under future climate.