Inflated membrane roofs were adapted to cover an open area for the EXPO-2001. The roofs has irregular form in plan nearly circle form and can be classified with diameters of 90, 65, and 55 m respectively. The roof Total Area is 18000m2. It consists of double layer inflated textile membrane structure supported on an outer steel ring beam, which is supported on vertical columns. The lower membrane layer was stiffened by cable net structure to reduce the total cost of the membrane roof..