Emission level is expected to be significant impact on climate change,which has a close relationship with local water resources.Based on different green gas emission scenarios,five relatively independent global climate models were selected from 47 CMIP5 models to simulate the future climatic conditions.This paper calculated the future water resources with the data of chosen models by downscaling them to local projection and correcting the bias,and then applying to the hydrological model.The results show that the water resources in the Dongting Lake Basin are likely to grow in the future and distributed more unevenly.In 3 scenarios,water resources increase during flood season and decrease during dry season,and the total amount grow prominently.More green gas emission,more severe the uneven distribution.