The construction of emergency water source of Jiujiang is of great significance for ensuring the life of people in Jiujiang and promoting the sustainable development of Jiujiang.Based on the characteristics of water resources of Jiujiang，the present situation of fresh water sources and main problems，the feasibility of using Saicheng lake as an emergency water source in Jiujiang is discussed from the geographical location，water supply and current water quality.The supply and demand analysis of the ecological water demand，water availability，water quality of Saicheng lake and emergency water volume is carried out.The results show that，the available water of Saicheng lake meets the demand，the water quality meets the requirements of source water quality，and the location is suitable.Therefore Saicheng lake is feasible as the emergency water source of Jiujiang city．