Recently, the LCCs (low cost carriers) using ICN (Incheon International Airport) as a hub have increased their international routes. In addition, foreign nationality airlines, including Middle Eastern carriers, have gradually increased their operations at ICN. This growth in carrier services has resulted in a more competitive market environment, and reasonable resource assignment has become an important issue for airport operators. Moreover, the airport will open a new terminal-T2 (terminal 2) in early 2018, and carriers will need to adjust their operations reflecting the utilization of newly assigned facilities. Motivated by this change, we investigate the differentiation of airport service perception as well as airline choice behavior by passenger groups at ICN. This paper employs a MNL (multinomial logit) model as well as a SEM (structural equation model). The results indicate that airline gate allocation is a significantly important value for passengers in terms of airport service perception and choice behavior. Passenger perception and choice behavior differ according to the selected carrier. This study concludes that it is significantly important to consider the characteristics of passenger perception and choice behavior to improve airport operational efficiency, particularly with respect to carrier facility assignment.