An assembling structure for a ceiling fan has a hanging rod, a hanging ball, and a hanging bracket. A top end of the hanging rod forms a bending edge. The hanging ball has a first hole and a supporting wall. The hanging rod is mounted through the first hole. The supporting wall has a supporting platform abutting a bottom surface of the bending edge. The hanging bracket has a ball mounting segment and a ceiling mounting segment adapted to be mounted to a ceiling. The ball mounting segment has a hanging hole. A diameter of the hanging hole is smaller than a diameter of the hanging ball. The hanging ball abuts downward a periphery of the hanging hole. The hanging rod is mounted through the hanging hole. With a large contact area between the hanging rod and the hanging ball, the structural strength is high.