Grid so-called "spatial structure" is a relatively "flat structure" is concerned, it has the characteristics of a three-dimensional effect, spatial structure can be seen as the expansion and deepening of the planar structure. Since the advent of the spatial structure, with its efficient mechanical performance, new aesthetic forms and quick and easy construction was welcomed. In need large span, stadiums, convention centers, cultural facilities, transportation hubs as well as a large industrial plant space, all saw traces of space structures. Through continuous development of the spatial structure of a century, in terms of structure, in addition to grid, mesh shell, membrane structures, tensegrity system, opening and closing new members roof, collapsible structures are spatial structures. Early twentieth century, the steel grid structure for the development of materials to provide the conditions and subsequently the aluminum truss rod is making more compact. In recent years, composite materials, especially the large number of new building materials have been developed, the development of spatial structure had a strong impact. Due to rising material application variety and strength of steel, the spatial structure is also more and more use of steel, steel pipes, steel bars, steel cables and even products. In large part, the spatial structure became a "space steel structure." With the advent of modern computers, some new theories and analytical methods, such as finite element method, the non-linear analysis, dynamic analysis, the spatial structure has been widely applied, as well as the spatial structure calculation and design more convenient and accurate, so that Now the ever-changing spatial structure, species diversity. Spatial structure can be said to have become one of the most important contemporary architectural structures and the most active areas. Grid structure is generally about the same size or smaller lattice unit (repeat) composed. Often used in roof structures.