Though with the rapid development of economic globalization and informationization, Chinese e-government development is still in its infancy with a long way ahead. Based on some resent research on today?s e-government in Guangdong, we propose a special model to describe business process in e-government affair operations. The model extends Finite State Machine Model by message passing, business logic and several kinds of constraint check. Using this model to represent governmental business process helps to capture the exact status of each process step, standardize service procedure, describe complex constraint in the process and bring flexibility into its customization, which eventually results in more efficient delivery of services and facilitates greater transparency in the administration of government. Furthermore, it offers new thoughts in representing business process.