Optimal design of finite-dimensional elastic structures is considered. The proposed method is based on the sensitivity analysis where the sensitivity formulation is written in general form for coincidental buckling load factors including limit points and bifurcation points. The proposed method is applied to the design of spherical lattice dome subjected to a concentrated load and a distributed load, respectively. The results are compared with those obtained by means of linear eigenvalue formulation. Imperfection sensitivity properties of the optimal design are discussed.