The main goal of my diploma thesis was to elaborate a study and realization of a preliminary design of a roofing system on the airport terminal building. The introducing short review on types of structural elements and systems used for the design of long-span roofing structures was accompanied by an overview of method used in static and dynamic analysis of spatial truss structures. The crucial part of my thesis was a preliminary design of a roof structure over an airport terminal building servicing five aircraft stands with all necessary facilities and services. In the following report there are three different ideas of this design: - Rectangle airport building covered by a roof consisting of 7 spatial steel arched trusses with the mutual distance of 11 m, bearing intermediate beams with roofing panels; - Hexagonal airport building covered by a roof designed like spatial shell of spherical shape over the hexagonal building; - Circular airport building covered by a roof designed like spatial shell of spherical shape over the circular building. In all three models of the designs only analyses necessary for the preliminary design of main bearing structural elements were performed, using computer design through SCIA computer program. Some selected results of these analyses are presented in thesis.