It is proposed to apply the "City Planning" concept for reconstructing complicated enterprise systems. However, considering current IT environment of utilizing commercial software packages, it is effective to start with designing an integrated infrastructure framework as the first phase of City Planning. This paper aims at proposing "EII Meta-model" as the integration framework that can optimize the overall enterprise systems from the City Planning point of view after examining the requirements of information infrastructure of e-business systems. EII Meta-model consists of "Integrated Information Infrastructure Map", "Service Framework" and "IT Scenario". The Integrated Information Infrastructure Map is the structured scheme which combines the processes to select and decide applicable IT and to deploy them with maintaining and operating functions of the information systems. The Service framework is a set of procedures to decide and evaluate the service-level. And the IT scenario is a migration scenario that the Integrated Information Infrastructure Map can follow the change of business and IT environment. Finally, we illustrate the case of information system for an online securities company, which is characterized by rapid change of business environment and applicable technologies, and demonstrate applicability and effectiveness of EII Meta-model