The　seismic　response　characteristics　of　a　cable-stayed　bridge　are　closely　related　to　the　structural　system.　At　the　same　time,　the　influence　of　the　height　of　the　gravity　center　cannot　be　ignored　in　the　structural　system　selection　of　cable-stayed　bridges.　For　convenience,　to　make　the　scheme　comparison　and　structural　system　selection　in　the　preliminary　design　stage　of　a　cable-stayed　bridge,　the　judgment　criterion　of　a　low　gravity　center　cable-stayed　bridge　was　proposed,　based　on　the　simplified　calculation　of　the　fundamental　frequency　of　cable-stayed　bridges　with　two　kinds　of　the　structural　system　and　combined　with　the　response　spectrum　analysis　method.　The　comparison　of　the　results　of　the　finite　element　model　and　the　calculating　results　of　the　criterion　showed　that　the　judgment　criterion　has　high　accuracy　and　reliability,　and　can　be　applied　to　the　preliminary　design,　the　scheme　comparison　of　cable-stayed　bridges,　and　help　select　structural　systems　in　the　preliminary　design　stage　of　cable-stayed　bridges.