While the social activities using Internet become generalized, the side effect of the information security violation is increasing steadily and threaten the countries which is not ready to prevent from offensive penetration such as the Information-fighter or Cyber-military. In this paper, we define the concept and characteristics of the modern Information-Warfare and analyze various kinds of threatened elements and also examine the recent trend in other countries. And introducing Computer Forensics raised recently for the confrontation against the security violation in the future, we will show the developing strategies and the necessity in order to response cyber attacks. These developing strategies can be used to ensure and re-trace the technical evidence for the security violation and to achieve the disaster relief effectively. So we hope that can apply them to the actual preparation through developing cyber trial test of the defense and attack for the Information-Warfare.