The Korean airspace is very much limited, but its users are many. Especially many special using airspaces for military aircraft are formulated within the Taegu Flight Information Region and it is so restricted for civil aircraft to use the military airspaces. However, as the demand of civil air traffic is increasing, positive cooperation among the users of the airspace is needed to cope with the demand and to uplift the utilitation of the Korean airspace. Most of airspace except airways within the FIR are restricted areas, prohibited areas or operation areas for the military purpose. This thesis shows how to improve the utilitation of the Korean airspace and how much economical benefit the suggestion gives.