At present Electronic Government System (EGS) is one of the hot points that study and develop. This paper models and analyses the EGS using workflow based on Petri Net. Firstly,the advantage of using Petri Net in workflow is explained,then the workflow - net model of EGS is built with combination of Petri Net and workflow,at last,the validity of the model is proved based on the theories of Petri Net,at the same time,the res...