Abstract: The installation scheme and analysis procedure of the steel roof of Macao Gym are presented. First, the interaction between main and secondary trusses in the roof is analyzed to identify their individual contributions to ap plied loading. Based on the results obtained above, the installation approach an d steps of the secondary trusses is determined. Then the internal forces, deform ation and support reaction in the trusses are traced and calculated during full construction process. The obtained results verify the applicability of the insta llation approach, and the joining gap between main and secondary trusses is suit able. Finally, according to the data provided from piling settlement experiment, the effect of the reaction and settlement on the steel roof structure performan ce is determined and the roof safety in the state of uneven settlement is chec ked.