A semiconductor package structure is provided. The semiconductor package structure includes a first semiconductor package that includes a first semiconductor die having a first surface and a second surface opposite thereto. A first package substrate is disposed on the first surface of the first semiconductor die. A first molding compound surrounds the first semiconductor die and the first package substrate. A first redistribution layer (RDL) structure is disposed on the first molding compound, in which the first package substrate is interposed and electrically coupled between the first semiconductor die and the first RDL structure.