In　order　to　evaluate　the　behavior　of　reinforced　concrete　columns　with　rectangular　hollow　section　subjected　to　axial　compression　and　biaxial　bending,　the　calculation　formula　of　load　capacity　and　moment-curvature　relationship　are　derived　according　to　the　distribution　type　of　neutral　axis　in　this　paper.　The　load　capacity　and　rotation　ductility　of　the　bottom　control　section　of　three　reinforced　concrete　specimen　bridge　columns　with　rectangular　hollow　section　under　different　axial　compression　ratio,　reinforcement　ratio　and　stirrup　ratio　are　analyzed　based　on　these　calculation　formulae.　The　M-x-M-y　interaction　curves　and　moment-curvature　curves　of　bridge　column　specimens　derived　from　the　theoretical　calculation　show　good　agreement　with　the　experimental　data　obtained　by　cyclic　testing　of　three　specimens　under　axial　compression　and　biaxial　bending.　The　results　show　that　the　P-M-x-M-y　interaction　has　considerable　effects　on　the　behavior　of　the　reinforced　concrete　bridge　columns　with　rectangular　hollow　section.　If　these　interaction　effects　are　ignored,　then　the　load　capacity　and　deformation　are　overestimated　and　this　fact　can　be　crucial　from　the　viewpoint　of　design.