Water pollution accidents such as chemical spill and toxicants leach have become a serious issue in the world,which brings great threats to the aquatic ecosystem and drinking water safety.To timely detect unknown pollutions and take proper emergency actions,this study developed a system which integrated an online intelligent water quality monitoring device and a high efficient water quality model.The device is based on water quality probes and biological sensors that use fish motion as indicator.The numerical model is a combination of Euler and Lagrangian approaches.Finite element method is applied to simulate the flow field in an unstructured grid,and the pollutant behaviours are traced through particle tracking.Oracle,ArcSDE and ArcIMS technologies are introduced to make the system WebGIS based so that improve the data receiving and dispatching efficiency.The developed system has been successfully operated in the Douhe reservoir and Taihu Lake,where drinking water intakes are installed.It is seen from the applications that on-line intelligent water quality monitoring and emergency support system can be of great support to emergency management.