Based　on　the　concept　of　the　base　forces　by　Gao,　a　new　finite　element　method　-　the　base　force　element　method　(BFEM)　on　complementary　energy　principle　for　two-dimensional　geometrically　non-linear　problems　is　presented.　A　4-mid-node　plane　element　model　of　the　BFEM　for　geometrically　non-linear　problem　is　derived　by　assuming　that　the　stress　is　uniformly　distributed　on　each　sides　of　a　plane　element.　The　explicit　formulations　of　the　control　equations　for　the　BFEM　are　derived　using　the　modified　complementary　energy　principle.　The　BFEM　is　naturally　universal　for　small　displacement　and　large　displacement　problems.　A　number　of　example　problems　are　solved　using　the　BFEM　and　the　results　are　compared　with　corresponding　analytical　solutions　and　those　obtained　from　the　standard　displacement　finite　element　method.　A　good　agreement　of　the　results,　and　better　performance　of　the　BFEM,　compared　to　the　displacement　model,　in　the　large　displacement　and　large　rotation　calculations,　is　observed.　(C)　2011　Elsevier　Ltd.　All　rights　reserved.