Indacenoids　are　polygonal　systems　consisting　of　two　pentagons　each　and　arbitrary　numbers　of　hexagons.　They　represent　a　class　of　polycyclic　conjugated　hydrocarbons.　A　fixed　bond　of　a　polygonal　system　is　an　edge　which　is　or　is　not　selected　in　all　the　Kekulé　structures　of　that　polygonal　system.　It　is　proved　that　each　catacondensed　indacenoid　has　some　fixed　single　bonds,　but　has　no　fixed　double　bonds.　Moreover,　the　location　of　fixed　single　bonds　in　a　catacondensed　indacenoid　is　identified.　Finally,　a　theorem　about　fixed　single　bonds　in　pericondensed　indacenoids　is　proved.