Although the Korean government is making great effort to prevent the redundancy in IT investment and efficiently allocate the IT budget, actual achievements are quite limited because of the variety of IT resources and different architecture description among organizations and projects. Thus, a standardized description model of the system architecture is strongly needed to identify the common resources and improve the efficiency of IT investment. Therefore, in this paper, we have developed the function-network matrix model which can be used as the basic template for a standard for architecture description of e-Government systems. The function-network matrix model integrates the function tiers and the network areas into a single unified framework, which enables the functionality of each component and the flow of information clearly visible. Moreover, we described the architectures of Korean e-government’s citizen service systems using our model, resulting in clear demonstration of the similarities and differences between different systems, and easy identification of the common resources. Using the architecture description model developed in this research, the consolidation of national IT resources can be promoted, and non-expert IT users can easily recognize the architecture of their systems. In addition, more efficient and systematic IT resource management can be achieved using our model.