Japan, South Korea, and Taiwan have similar economic backgrounds, as they have undergone the aftermath of destruction and restructuring from the World Wars, and they are all situated in important locations in the East Asia region. Since there have been abundant research studies about competition in economic growth, international trade, and technology advances, however, there competition might also be competition between these countries in the fishery industry. Resulted of Western and the Central Pacific Ocean (WCPO) has been one of the most valuable fishery areas in the world, we use the tuna capture data from the Western and Central Pacific Fisheries Commission (WCPFC) and utilize a cointegration test and error correction model in a time series analysis to analyze the competitive relationship in the three countries. In our study, we found that if the Japanese captures increase, the Taiwanese captures also increase and the same cases occur in the contrasting cases. But the relationships with South Korea and Japan or with South Korea and Taiwan are negative. It represents that the capture in the three countries impact each other. We also try to find the reasons for impact and long-run and short-run competitive relationships.