Abstract
With growing competitions, companies using cloud computing to reduce IT cost are increasing. However, it is considered that strategic information system supporting execution of company strategy is not fit for cloud com-puting. It's because company specific strategic requirements are included in strategic information system, and also seek special support when using cloud computing. To achieve IT cost reduction, narrow down the specific requirements and integrate the development of specific requirement into the installation work of cloud standard services. Additionally, it is necessary to minimize the impact of joint operation in cloud computing. Valid methodology for achieving cost reduction in the development of strategic information system using cloud com-puting is proposed in this research paper.