A method of fabricating a package structure including at least the following steps is provided. A carrier is provided. A first package is formed on the carrier. The first package is formed by at least the following steps. A first redistribution layer is formed on the carrier, wherein the first redistribution layer has a first surface and a second surface opposite to the first surface. A semiconductor die is bonded on the first surface of the first redistribution layer. The semiconductor die is electrically connected to the first redistribution layer through a plurality of conductive wires. An insulating material is formed to encapsulate the semiconductor die and the plurality of conductive wires. A thinning process is performed to obtain an insulating encapsulant by reducing a thickness of the insulating material until a portion of each of the conductive wires is removed to form a plurality of conductive wire segments, wherein the semiconductor die is electrically insulated from the first redistribution layer after the thinning process. A second redistribution layer is formed on a top surface of the insulating encapsulant, and over the semiconductor die. The second redistribution layer is electrically connected to the first redistribution layer and to the semiconductor die by the plurality of conductive wire segments.