Abstract: In order to do the topmost design of integrated information system(IIS)，we should comprehend the IIS in the business aspect rather than in the software development aspect. In the users’ point of view， the IIS’s function requirement and organization command structure must be taken into account. Thus implements the IIS’s flexible structure. The background management of software development environment should also be considered. The topmost design of IIS will accommodate the bidirectional evolvement of military business system and software environment. The IIS users should turn the tables on technical driven and become the dominant role of informationization. They should participate deeply in evaluating and selecting the technical scheme and products， as well as mastering the frequency and ways of system upgrade.

Key words: Military system, Integrated information system(IIS), System model, Service-based architecture, Background management, Technology adoption