Purpose – The purpose of this paper is to propose a design alternative to ensure that Carbon Border Tax conforms to WTO-related regulations, and to present Korea’s strategic countermeasures in this regard. Design/Methodology/Approach – The rationale for the implementation of the Carbon Border Tax was explained in terms of economic theory and environmental policy, and trends in international discussions in major countries were examined. Findings – The legal basis on which Carbon Border Tax can be permitted by WTO agreements results in exceptions to Article 20 of the GATT, and it must be designed in an according direction Articles 20 (b) and (g) of the GATT Article 20 exceptions. Research Implications – Carbon Border Tax is being introduced around the EU and the United States. Then the domestic industry will be hit in some way. Therefore, Korea should also prepare countermeasur against Carbon Border Tax introduction. As a countermeasure, first, various support measures should be prepared to help domestic companies participate in the “RE100.“ Second, in order to protect the export industry and prevent the decline in the international competitiveness of its products, the country should pursue more active energy conversion policies, such as reducing the proportion of coal power generation and increasing the proportion of renewable energy. Third, in the process of establishing international norms related to CBAM in terms of trade diplomacy, it is necessary to actively participate in bilateral or multilateral consultation processes. Fourth, we need to upgrade green information.