A semiconductor package structure includes a first semiconductor die having an active surface and a passive surface opposite to the active surface, a conductive element leveled with the first semiconductor die, a first redistribution layer (RDL) being closer to the passive surface than to the active surface, a second RDL being closer to the active surface than to the passive surface, and a second semiconductor die over the second RDL and electrically coupled to the first semiconductor die through the second RDL. A first conductive path is established among the first RDL, the conductive element, the second RDL, and the active surface of the first semiconductor die.