Based on the communication system model in the Information Theory, a three-dimensional domain concept model is proposed to depict domain exactly. Thefirst dimension is information encoding format; the second one is action of information operation; the third one is atomic goal of information system. A micro-component model, which is the basic unit to construct arbitrary components, is proposed and depicted exactly in the projection on the encoding-action plane of the three-dimension model. Using the method of PAD(projection analysis of domain), a common domain architecture modeling method based on the soft-bus is proposed to resolve the problems in the modeling. The soft-bus can transmit the mixed structure of information flow and control flow in the architecture, divide the collaboration policy from the function services and predigest the control operation for domain architecture. The method above is applied in the e-government domainas an instantiation. SoftProLine, a flexible software produce platform, is given as a customizing tool to develop various e-government applications. It can satisfy the requirements of users with high quality, high flexibility and high efficiency.