'Credible deterrence' is one of our military strategic concepts. Among the development of numerous deterrence concepts, the cost-benefit should be calculated extensively in order to find out the possible 'losses' which the adversary would get. Besides the military actions, using the logical thinking to calculate the cost-benefit will make the deterrence decision clearer and provide a new level of concept to successful deterrence operation, especially for those issues as inaction, misjudgment and advanced judgment of the adversary.