In order to develop a new type of rock protection barrier having absorbing capacity of 500 kJ and small deformation, 3D elasto-plastic FE analysis for the prototype rockfall protection fence was carried out. Here, proposed numerical analysis method was verified comparing with the experimental results. After that, parametric numerical analyses were carried out varying number of spans and intervals between posts. From this study, the following results were obtained: 1) experimental results of the deformation of fence and applied tensile force for each rope can be properly estimated by means of the proposed FE analysis method; and 2) effects of number of spans and intervals between posts on protection performance of the fence were numerically clarified.