Abstract: This paper focuses on the feature that shape and internal forces are coupled for a cable-net structure. Equilibrium equations of the free nodes of a cable-net are established. Incremental equilibrium and compatibility equations of the nodal displacements and the cable forces are derived. The nonlinear equations are solved by iteration method. Two examples are given. The proposed approach proves to be feasible for determination of the initial equilibrium state and the loading state of cable-net structures.