What should the House of Councilors be under the Constitution? This has been one of the most difficult problems under our constitution since its establishment. It is such a thorny problem that we cannot resolve it at present. This research attempts to provide the proper answer concerning it. Of course, the constitutional position of the House of Councilors should be prescribed in correlation with the House of Representatives on the basis of the characteristics of the political and social background of the country in question. This research concludes that the House of Councilors should be a guardian of the Constitution, which can control the government from the perspective of protecting the constitutional discipline. If the government forces through its policy without any public agreement, nobody but the House of Councilors cannot stop its forcible passage. The House of Councilors is therefore responsible for supervising and preventing the government from overstepping its own authority. This research explains the validity of such a position of the House of Councilors in light of the text and the original intent of the constitutional law, the constitutional theory, and the actual political life. And then this research describes that the House of Councilors should establish such new committees as the constitution committee and the delegated legislation committee, and be provided with such new power as the legislative veto, with which the House of Councilors can veto any problematic delegated legislations made by the government, for protecting the constitutional norms. Furthermore, more than half of the members of the House of Councilors should be non-partisan. In order to establish such a composition, we have to fundamentally transform the current electoral system. And in all probability, a recommendation system for candidates who are non-partisan and knowledgeable would be suitable for this purpose. When these reforms are put into practice, the House of Councilors will become the genuine "House of Common Sense".