Distributions　of　the　residual　stress　of　U-rib　stiffened　plates　and　influences　of　some　factors　such　as　width　and　thickness　of　plates　were　investigated　by　numerical　analyses.　A　simplified　calculation　method　of　the　residual　stress　of　U-rib　stiffened　plates　was　proposed.　The　result　shows　that　the　width　of　plates　has　little　influence　on　residual　tension　stress,　but　it　has　a　major　effect　on　residual　compression　stress.　The　residual　stress　distribution　in　plates　and　U-rib　stiffeners　was　influenced　by　the　ratio　of　thickness　of　plate　and　U-rib　stiffeners.　In　the　analyses　of　compression　capacity　of　U-rib　stiffened　plates,　the　simplified　distribution　of　welding　residual　stress　can　be　used　and　the　results　were　very　close　to　that　by　the　numerical　simulation　method.