After formally defining the examination and approval of business, a formal dynamic behavior model for examining and approving business, called EABWF-net, was established. The model was different from traditional process-oriented model. It centered on the examination and approval role taking the message as roam mechanism and rule as flow logic of business. The model overcomed the limitation of traditional modeling method that lacks process suppleness and system flexibility. Furthermore it can explain the examination and approval business clearer and more directly.