Abstract: A nonlinear finite element model is presented for the pres-tressed flexible cable which takes into account the effect of initial deflection on stiffness using a conversion modulus of elasticity. To overcome the ill-condition of stiffness matrix caused by cooperation of flexible and stiff elements, Master—Slave relations between the modal displacements are introduced. And then a new stiffness matrix iteration method with movable nodal coordinates and Maste-Slave relations is developed to analyse flexible compounded structures such as cable-stayed bridges, suspension bridges etc., in which the equilibrium equations set up for the structure subjected to deflection. The method developed in this paper has been successfully applied to analyse many cable-stayed bridge structures in practice. Usually a satisfactory accurancy can be obtained after 2 to 6 iterations.