In this paper, by considering the Middle Route region of Water Transfer from South to North as background, the South Part of Haihe River basin(SPHR) is selected as the representative area for the North China region. System Dynamics (SD) model of SPHR water resources system is established, and the variation trends of water supply and demand under different hypothetical climate change scenarios are predicted by simulation. The prediction results show that climate change will disturb the operation of SPHR water resources system, especially affect its economic growth rate However, within the range of climate change (ΔT≤18℃,ΔP≥-024%), climate change can not change the operation law of SPHR water resources system, which is controlled by internal driving factors, such as economy growth, science and technology development, population increase and water saving improvement, etc. The results also verified the certain tendency of zero increase or negative increase of water demand and water shortage in future under the conditions of technology development and water saving improvement. The results provide the quantitative reference indexes for water demand management and water saving improvement, and also supply the necessary basis for decision making on economy planning and water transfer.