A semiconductor package includes a first die, a second die, a molding compound and a redistribution structure. The first die has a first conductive pillar and a first complex compound sheath surrounding and covering a sidewall of the first conductive pillar. The second die has a second conductive pillar and a protection layer laterally surrounding the second conductive pillar. The molding compound laterally surrounds and wraps around the first and second dies, and is in contact with the first complex compound sheath of the first die. The redistribution structure is disposed on the first and second dies and the molding compound.