Abstract: As the occurring frequency and intensity of drought is in increase, drought affects both water volume and water quality. Considering from the drought impact to environment, drought events are considered to be more dangerous due to their moderateterm, longterm and largescale impacts. The joint effect of temperature increase and runoff volume reduction results in a deterioration of water quality, and water quality during drought period is also affected by land use change, regional climate change and human activities. Nonpoint source pollutant is currently the main factor resulting in water pollution in drainage basin, and the entering time and content of nonpoint source pollutants are the main factors polluting waters during drought period. A lot of nonpoint source pollutants are eroded into waters due to the accumulation of pollutants during drought period and the increase of precipitation intensity after drought. Therefore, droughtrewetting cycles may impact water quality more significantly.