LGBT movements have been actively taking place since the late 20th century, 24 countries around the world have fully embraced same-sex marriage as a form of marriage, and implemented it into law. Therefore in this paper, arguments and discussion on prohibition of discrimination due to homosexuality are examined and reviewed under the Constitution of Korea, by looking at the discussion on homosexuality (sexual orientation), which is currently in progress in Korea. However, First, national consensus is deemed absolutely necessary to add a new prohibition ground. Second, specifying the grounds for prohibiting discrimination should take into account historical background and demands of the “oughtness.” Third, it should be noted that the grounds for prohibiting discrimination specified in the Constitution are not subject to moral judgment. Fourth, in the case where homosexuality and/ or sexual orientation are specified as grounds for prohibiting discrimination, the problems that may occur must be considered. the 「National Human Rights Commission Act of Korea」 Article 2, Subparagraph 1 defines the concept of “human right(s),” and also in Subparagraph 3, “sexual orientation” is enumerated as an example of “discriminatory act.” Therefore,「National Human Rights Commission Act of Korea」 Article 2, Paragraph 3 must be deleted.