Abstract: Due to its special characteristics like hard to predict, difficult to deal with and strong destructive power, emergency study attracts more and more attention. Clear description of emergency is the basis of its related research. Firstly, this paper collects and sorts some typical emergencies. Secondly, it extracts emergency attributes by the approach of multi-case study to describe emergencies structurally, and furthermore, subdivides them to a set form including the event type, the key attributes, the secondary attributes, the environment attributes, and the hazard assessment attributes. Finally, it employs Wenchuan Earthquake which is a typical historical eventome historical events to verify this structural description framework. All these studies make sense on the research of emergency evolution law or corresponding decision- making.