This study is aimed to investigate the application of DITA(Defense Information Technical stAndard) on the weapon information systems and defense management information systems in order not only to update the current DITA version 4.0, but also to develop SoS(System of systems) interoperability policy in the armed forces of Korea. For this study, 18 information systems were considered, their development products(System/Sub-system Specification, Technical architecture View, System Interoperability Test and Evaluation products) were reviewed and analysed. As a result of the investigation and analysis, it was found that the 44% of the DITA standard profiles were used for the development of the defense information systems. We conclude that DITA should be updated to be a minimal set so that all the defense information systems should be DITA-compliant. And it should be reviewed periodically to reflect the new information technology.