Abstract: Elasto-plastic response time-history analyses of a long-span hangar based on site-class Ⅳ were performed under 3 seismic inputs of rare major earthquake for the seismic fortification intensity of 7,using direct integration method.Dynamic responses of the structure subjected to one-dimensional and three-dimensional earthquake inputs were compared.The results show that,with three multi-dimensional earthquake inputs,more plastic hinges of its supporting columns appeared,and for some of them,the plastic damage got worse;The maximum lateral displacements of the structure and the maximum internal forces of its columns are increased slightly;whereas,the roof structure were influenced more obviously,the number of hinges and internal forces of roof members got significantly increased.