This report shows us a comprehensive analysis and research on the technological system of Japan’s submarine detection and anti-submarine capability. It points out the reasons and motivations behind Japan’s valued technology of submarine detection and anti-submarine capability. The report introduces Japan’s R&D system and the level of equipment used in submarine detection and anti-submarine activities. With an overview of the techniques, tactics, equipment level and overall capabilities of submarine detection and anti-submarine activities in Japan, the report makes preliminary analysis on the future development possibilities and countermeasures.