This study used the Unpaywall API, one of the open tools to track the OA version, to empirically identify the OA of 3,905 papers that have been published by Korean corresponding authors since 2015 in international journals. As a result, the following facts were found. First, less than 30% of papers have been open accessed, and more than half of them were bronze OA. Secondly, the archiving site of the Green OA papers was found not to be domestic but mainly subject repositories or institutional repositories of overseas universities to which co-authors belong. Third, only 19.6% of research fund granted papers were open accessed and half of them were in the medical field. In contrast to the international trends in which the OA papers showed higher citations, the analyzed OA papers showed no higher citations than the non-OA papers.