Response　surface　methodology　was　in　good　use　as　a　method　of　replacing　the　complex　sensitivity　analysis　in　the　field　of　structural　optimization.　Its　time　cost　increased　rapidly　with　the　increase　of　the　number　of　design　variables,　for　this　disadvantage,　provided　the　theory　of　constructing　structural　displacement　with　basis　function,　combined　with　response　surface　methodology,　the　examples　of　truss　section　optimization　illustrate　the　feasibility　and　efficiency　of　the　theory.