The Article 24 of the United Nations Charter prescribes the responsibility of the Security Council in maintaining the peace and security of the international community. Due to emerging threats against international peace, such as terrorism, proliferation of weapons of mass destruction and increasing recognition of the ‘ human security’concept, the Security Council now needs to diversify approaches to international security, such as prevention by establishing new international norms through quasi-legislation activities, in addition to a conventional approach of response to crisis such as peace keeping. Thus, the reform of theSecurity Council must be considered so that the Security Council could deal with such new threats more effectively as well as more legitimately.