The purpose of this study is to figure out structural differences among aviation networks of Korea, China, and Japan through analyzing their major airports’ and air carriers’ networks in the international aviation market. This study employs three (degree, betweeness, closeness) centrality, network density, and assortativity measures in the network analysis, in order to evaluate international connectivity of airports and air carriers operating in the three countries. The main results are as follows. First, ICN (Incheon International Airport) is positioned as a top-tier airport among major airports in Asia, in terms of international connectivity evaluated by the three centrality measures. Also, we confirm that the connectivity of secondary hubs in China and East Asia markets has rapidly increased from 2015 to 2019, according to increasing routes connecting between those regions. Next, through comparing major airports’ networks of the three countries in East Asia, we find that in Korea the centrality gap between ICN and the rest of international airports is larger than gaps among major airports in the counterparts, mainly affected by their hub network structures. However, LCCs (Low Cost Carriers) in Korea have the smaller dependence on ICN than FSCs (Full Service Carriers) according to operating regional airports as their secondary hubs. From the results, we confirm that it is necessary to pursue improving the international connectivity of regional international airports through expanding LCCs’ air networks as a suitable strategy to improve the accessibility to international flights for local residents, as well as to alleviate the imbalance of the national airport system.