Abstract: SWAT, a distributed hydrological model, is used to simulate and analyze spatiotemporal characteristics of blue and green water resources in the Lianshui basin under the long-term climate change effects of 1996-2015 and 2020-2079. Climate change have been divided into three climatic background periods of 1996-2015, 2020-2049, 2070-2100, and into 9 climate change scenarios according to inputs of the future climate conditions, which were generated from HadGEM2-AO atmospheric model in typical concentration path of the rcp2.6, rcp4.5, rcp6 and rcp8.5. PSO particle swarm optimization algorithm in combination with Kling-Gupta efficiency coefficient KGE objective function is introduced to calibrate the model parameters based on Xiangxiang station measured discharges and MOD16 evapotranspiration data. Moreover, p-factor, r-factor, R２, NSE and PBIAS are also performed to evaluate the model simulation results and uncertainty, and the results indicated good performance of simulation for blue and green water both in the calibration and validation period. Consequently, scenario analysis result shows that Lianshui river basin has different-varied levels of decrease in blue water（1.4%-17.3%) and green water storage（7.8%-19.7%) while the green water flow（3.5%-12.4%) increases in different RCP concentration path scenarios during the climatic background period of 1996-2015, 2020-2049 and 2050-2079.Even taking parameter prediction uncertainty 95ppu range into consideration, the future growth trend of green water flow is also obvious. Hence, taking green water resources into the future water resources evaluation strategies to achieve blue water and green water comprehensive planning and management is indispensable for the Lianshui river basin.