Single-layer steel latticed strucutures have been used as large roof structuress for their lightness and beauty. But recently, new multi-story buildings employing latticed structural walls begin to be built. In seismic region such as Japan, strong earthquake load is most critical for such latticed structural walls. In this laboratory, buckling and post-buckling behavior of latticed structure has been studied to use them as seismic-resintant elements in buildings. The study comprises experiments, theoretical and numerical analyses. Plus, seismic response of gymnasias in which large steel roofs lies on lower concrete frames is extensively investigated through experiments and response analysis.