An efficient method for finding initial shape of cable system by nonlinear displacement analysis is presented in this study. The supports of a cable system are first moved from a reference position to the specified boundary and the equilibrium position is then determined by the Newton‐Raphson iteration method. During analysis the large displacement effect is taken into account. The determined shape provides the geometry as well as the prestress distribution of the cable system. In general, the prestress of cable members may be too large or too small in the equilibrium position. So some modifications must be carried out in order to obtain a reasonable initial shape with suitable element length and prestress distribution. This method works well and can be applied to any cable system having an arbitrary form.