This research studies the adequate size standard of Seogwipo cruise terminal CIQ facility that is scheduled to be built around Gangjeong harbor area in Seogwipo-city. In order to respond to the highly increasing number of passenger cruise ships compared to Seogwipo cruise terminal design in 2010, the adequate size standard of Seogwipo cruise terminal CIQ facility was examined for passenger service level grade. Based on size computation elements such as the number of passengers of cruise ships with the largest size of port entry, ship landing rate, passenger processing ratio, and surge factor, the CIQ facility size for each service level grade was reviewed. As a result, the area of 2,971m2 (A grade), 2,409 m2 (B grade), and 2,088 m2 (C grade) were computed. This showed that the area of B grade was about 82% and C grade 70% compared to the area of A grade. The CIQ facility size computed for each service level grade in this research was analyzed that its area needed to be increased by 322% at least and 458% at most, compared to the CIQ facility area of 649m2 of the existing design (2010). In order to respond to the increasing number of cruise passengers, provide high-level passenger service, and improve the international image of Jeju, Seogwipo cruise terminal should secure the size that is equal to or higher than the B grade of service level.