Abstract: Based on the Petri net theory, ECA rules was researched and a basic Petri net model was established. Special research was made on how to use a Petri net to express compound event ECA rules, and an extended Petri net system was put forward. Considering the feature of ECA rules in general, the Petri net model based on an ECA rule system reflects the system feature of ECA rules in all aspects. Through forming the reachability tree and transition sequence, the ECA rule system and its action feature can be understood clearly, and rationality verification on the rule system is convenient to make and to help a system administrator to analyze and manage it.