Earthquake response of long-span space truss structure is generally analyzed by the use of equivalent continuum shell theory, because the enormous number of nodes and members of the structure makes the computation quantity very huge when it is treated as frame structure. Efforts have also been made to reduce the degrees of freedom by statical mass-condensation method. But it is certainly difficult to trace the behavior of the truss structure by shell theory when buckling behavior of members is taken into consideration. By comparing the analytical results of a full degree-of-freedom model and a reduced degree-of-freedom model in this paper, it is concluded that a model with all degrees of freedom is necessary for elasto-plastic analysis of earthquake response. In this paper, a full degree-of-freedom model is applied to 5 double-layer cylindrical truss structures, which have the same span length of 200 meters and differ from each other either in rise or in length perpendicularly to the span. Earthquake response analyses are carried out with consideration of the buckling behavior of the members. It is found out that for cylindrical truss structures considered in this paper, close attention is required for horizontal movements which are perpendicular to the span. For statically indeterminate structures, even if a certain member buckles and fails to bear the load caused by self weight of the structure, the whole structure system will not collapse immediately. It is only when the buckling members increase to a certain number, the structure fails to support its own weight and collapses.