This article presents scenarios of North Korea’s Denuclearization and Korean Unification at North Korean sudden change. The North Korean sudden change will be a critical event on North Korea’s denuclearization and Korean Unification. The end state of North Korean sudden change will be variable by the seriousness of the crisis, the ways of intervention by stakeholders, and whether they can reach the agreement for the unification of the Korean Peninsula. The first scenario is North Korea will fix the crisis before neighboring countries``s intervention. If North Korea can``t deal with the crisis, neighboring countries will intervene to secure NK’s WMD. Intervention by China is the second scenario, and co-intervention by stakeholders is the third scenario. The first and second scenarios are negative to achieve the goals, North Korea’s Denuclearization and Korean Unification. The third scenario is relatively positive to achieve the goals.