A package structure includes a redistribution circuit structure, a wiring substrate, a semiconductor device, an insulating encapsulation, and a reinforcement structure. The redistribution circuit structure has dielectric layers. The wiring substrate is disposed on the redistribution circuit structure. The semiconductor device is disposed on the redistribution circuit structure opposite to the wiring substrate. The insulating encapsulation laterally encapsulates the wiring substrate. The reinforcement structure is partially embedded in the redistribution circuit structure and is partially embedded in the insulating encapsulation. The reinforcement structure includes reinforcement pattern layers and reinforcement vias. The reinforcement pattern layers and the dielectric layers are stacked alternately. The reinforcement vias penetrate through the dielectric layers to connect the reinforcement pattern layers. The reinforcement structure is electrically floating.