Folded　graphene　nanoribbons　(FGNRs)　have　attracted　great　attentions　because　of　extraordinary　properties　and　potential　applications.　The　atomic　structure,　stacking　sequences,　and　electronic　structure　of　FGNRs　are　investigated　by　first-principle　calculations.　It　reveals　that　the　common　configurations　of　all　FGNRs　are　racket-like　structures　including　a　nanotube-like　edge　and　two　flat　nanoribbons.　Interestingly,　the　two　flat　nanoribbons　form　new　stacking　styles　instead　of　the　most　stable　AB-stacking　sequences　for　flat　zone.　The　final　configurations　of　FGNRs　are　greatly　affected　by　the　initial　interlayer　distance,　stacking　sequences,　and　edge　styles.　The　stability　of　folded　graphene　nanoribbon　depends　on　the　length,　and　it　can　only　be　thermodynamically　stable　when　it　reaches　the　critical　length.　The　band　gap　of　the　folded　zigzag　graphene　nanoribbons　becomes　about　0.17　eV,　which　provides　a　new　way　to　open　the　band　gap.　(C)　2013　AIP　Publishing　LLC.