To　avoid　the　complicated　dynamic　sensitivity　analysis,　the　response　surface　methodology　(RSM)　is　adopted　in　structural　dynamic　optimum　design.　The　approximate　explicit　of　frequency　constraints　is　established.　The　optimization　model　of　plate　and　shell　structures　is　constructed　and　it　is　solved　by　Lemke　method.　Numerical　examples　show　that　this　method　is　accurate　and　efficient.