The United Nations（UN）practices of substituting Member States' operationsauthorized by the Security Council―what is called, an "authorization" model―for a predeterminedChapter-VII mechanism have been generally accepted among states. Mostinternational scholars regard the said practices as acceptable measures for restoring internationalpeace and security within the present UN framework, even though this is farfrom what the UN founders originally envisaged. However, it seems to be inadequate tostudy, understand, and assess 'what Security Council actually authorizes for MemberStates' and 'what kind of legal relationship the authorization establishes between the UN（Security Council）and authorized Member States', because relevant legal theories onthe substance and content of authorization are insufficient to provide effective solutionsand significant guidelines for addressing practical matters engendered by authorized operationson the ground. Therefore, it is necessary to rethink the "authorization." The key tounderstanding authorization requires a focus on the complex and mixed structure of thenormative and formal relationship―verticality―based on the UN Charter on the onehand, and an effective and practical relationship―horizontality―based on effectiveness,pragmatism and interests on the other hand, between the UN and the authorized MemberStates.