This paper presents a theoretical investigation for the form finding and the loading analyses of membrane structures by using the finite element package ANSYS. The tension structures under loading usually involve large displacements, so the non-linear theory is applied in theinvestigation. It is found that the results of form finding depend on the following factors: the meshing, the elastic moduli of the membrane material, the initial stress in the membrane, the stress in the boundary cables and the ridge c...