Abstract: A ceiling fixture mounting structure including a ceiling fixture holder fixed to the ceiling around the wire hole on the ceiling, a circular mounting plate detachably fastened to the ceiling fixture holder by swivel joint and having a connecting block with a cut at the center, and a ceiling fixture body fastened to the mounting plate by screws, wherein by matching the cut on the connecting block with a stop plate on the ceiling fixture holder, the mounting plate is accurately fastened to the ceiling fixture holder, causing the contact metal plates of on the connecting block respectively and positively disposed in contact with the contact metal plates on the ceiling fixture holder.