1. The ”All-out National Defense” idea has long been promoting by the ROC Government. The fundamental task of national defense is to protect its citizen, to cultivate national strength, and to maintain its national interests. ”National Security” is supposed to be the common language to the people and ”All-out National Defense” is responsibility to all the people.2. This essay takes qualitative research as basis for theoretical explanation, through which data that are relevant to defense affairs and national security can be collected and analyzed so as to understand the trend of national security and its future development.3. Nowadays, countries worldwide have acknowledged the importance of all-participated national defense, especially focused on the trend of all-out defense promoted by states around the world, in the hope that this trend may become references for ROC's military build-up and military buildup in the future.