Abstract: Beam-string (frame-string) structures have been adopted in several large-span structures in China. However, theoretical analysis of this kind of structures has not been well established. Some problems in the design and construction of beam-string structures are presented and discussed including the pre-stress distribution of each element corresponding to the initial geometry and the simulation of construction process. First, the equilibrium matrix theory is extended to the analysis of hybrid spatial structures composed of beams, bars and cables and a general form of the equilibrium matrix of two-node beam element and bar element is also derived. Using its total equilibrium matrix, a small beam-string structure is analyzed and only one independent self-stress mode is obtained. Secondly, another method, named as local analysis method, is presented where the whole structure is divided into two parts: the upper structure and the lower structure. It can also be used to obtain the initial pre-stress distribution and the zero-state geometry of the upper structure. Numerical examples are given to verify the methods.