To　study　the　mechanical　properties　of　plate-rod　system　for　scoliosis　(PRSS),　a　model　of　scoliosis　and　correcting　clamp　was　built　on　the　base　of　similar　principle.　According　to　the　factual　situation,　the　distribution　of　model　centrum　stress　was　measured　by　using　photoelastic　method　and　the　stain　of　the　spine　was　tested　by　strain　gauges　method　simultaneously.　The　results　indicated　that　compressive　stress　was　formed　on　the　convex　side　of　scoliosis　model　by　the　effect　of　portrait　loading.　On　the　other　hand,　when　PRSS　was　applied,　compressive　stress　of　the　concave　side　of　model　centrum　came　to　little　and　became　tensile　stress　with　transverse　correcting　loading.