We propose an improved M-ISMS(Military-ISMS) model which is based on common ISMS model for regarding military's unique characteristics. Our model focuses on 'Internal Security Audit' and 'Management of external activity' as military circumstances. So, we added the six control new items as internal security audits. Because the confidentiality is more important than availability in military service as compared with private sectors. In addition, we propose some control suggestions for establishing security management standards and keeping level maintenance when it will becomes to lose a value as confidential. The M-ISMS model in this paper has effectiveness which prevents security incidents in advance rapidly throughout a variety of common ISMS's advantages and security incidents of private sectors in consideration of military characteristics.