life of the Earth. Warmer climate conditions intensify water cycle, precipitation and also change the amount of runoff and its appearance time. Current study tries to use hydrological modeling for assessment of the impacts of climate change on rainfall and runoff of Khansar city. Nowadays protecting land cover, quantity of water resources are important. Surface runoff is one of most important reasons of soil erosion which causes sediment in reservoirs and reduction of lands feritility and also quality reduction water of rivers. So the main issue is exact prediction of basin runoff to raining events. The hydrologic models are simplifield models of real hydrologic system that helps us with studying surface runoff of basin in reaction to different entryes and also better understanding of hydrologic processes. According to variety of accessible rainfall-runoff models choosing an appropriate rainfall-runoff model for a basin can be important for efficiency, planning and water resources management. Therefore choosing a model needs recognition capability and limitations of basin models. So in this study the efficiency of three IHACRES, AWBM and SIMHYD rainfall-runoff models were evaluated and compared. Some criteria of evaluation in this study are Nash coefficient, coefficient of determination (R 2 ) and amount of overall error in flow volume (BIAS). Joint periods of simulation in these three models are chosen in a 30 year period. The simulation shows that SIMHYD with 0.566 Nash coefficient and IHACRES with 1.903 BIAS have the highest and lowest efficiency in calibration period. These amount are 0.554 and 2.06 for validation period. In the other part of the research, the impacts of climate change on watershed run-off were used. The results indicated that significant reduction in run-off would occre. Keywords : Climate change, Khansar, Rainfall-Runoff models, IHACRES, AWBM, SIMHYD