A collapsible wheel structure for a luggage box includes a wheel base and a foldable rod. The wheel base is pivotally connected with a wheel. One end of the wheel base is pivotally connected to the foldable rod. The foldable rod is pivotally connected to the wheel base for connecting with the wheel base firmly. When the wheel base and the foldable rod are unlocked, the foldable rod is in a folded status. The collapsible wheel structure is adapted to couple with the bottom of the luggage box. When the foldable rod is in a folded status, the size of the luggage will be reduced.