Abstract: A dome shaped roof structure suitable for a stadium for indoor athletic sports is disclosed. The dome shaped roof structure comprises a main frame for covering the inside of the stadium and a reinforcing frame. The reinforcing frame comprises: cables disposed in the inner side of the main frame and extended radially from the central portion of the main frame to the bottom peripheral border; circular cables disposed concentrically about the peripheral border of the main frame; and strut members that have each upper end connected to the steel member of the main frame at an intersecting point of the radiating cables and the circular cables, and the strut members vertically supported by the radiating cables and the circular cables; and wherein tension is introduced to the radiating cables in the direction of the bottom peripheral border and the outer ends of the radiating cables are fixed with the main frame, so that the steel members of the main frame are thrust up by the strut members of the reinforcing frame.