By delivering effective, in-situ conservation of biodiversity, OECMs can contribute to sustaining existing biodiversity values and improving biodiversity conservation outcomes. In this study, for the reporting of OECMs required by Kunming-Montreal Global Biodiversity Framework, the site-level assessment of the Korea National Arboretum and Buffer Zones were conducted using the assessment tool of IUCN. The site-level assessment was carried out in three steps(step 1: screening, step 2 : consent for full assessment, step 3 : the full assessment). It was found that the criteria were satisfied except for the consent for full assessment, sustainability of governance and management arrangements, and the equity of governance and management. Although the governing authority, rights-holders or any other stakeholders could be identified, the step of acknowledging and agreeing to the full OECM assessment was not possible because the governance was not established. As a result of the assessment of equitable governance and management in the aspect of recognition, procedure, and distribution based on criterion(the equity of governance and management), it is judged that more specific measures are needed in the aspect of recognition. And in the aspect of procedure, there is no legal basis for participation in governance and collection of opinions, so it is judged that there is a limit to listening and reflecting the opinions of stakeholders. In the aspect of distribution, it is necessary to further confirm whether it provides direct benefits to rights-holders such as landowners in the region. And it is necessary to prepare specific criteria to assess the important biodiversity values. Therefore, in order to promote OECM reporting in the future, it is necessary to conduct detailed research on various types of governance establishment and operation plans that can establish the basis for recognizing and agreeing to OECM assessment, specific criteria and reasonable measures to judge equity, and important biodiversity value.