This study examined the changes in intra-industry trade of the Korean paper industry while analyzing the trade structure of the industry from 2000 to 2021. The results are summarized as follows. First, most paper industry products exhibited intra-industry trading, and the portion of intra-industry had grown. The intra-industry trade included recovered, printing, sanitary, kraft, and corrugated papers as well as cardboard. Second, more products, including sanitary, kraft, and corrugated papers as well as cardboard, were included in vertical intra-industry trading. Third, with the exception of sanitary paper, most vertical intra-industry trade showed inferior vertical intra-industry trade. An increasing part of the intra-industry trade in the paper industry showed the intensified integration of international trade. However, reducing inferior vertical intra-industry trade could be a challenge for the future development of the Korean paper industry. © 2022 Korean Technical Assoc. of the Pulp and Paper Industry. All rights reserved.