A semiconductor package structure, comprising: a first semiconductor package, comprising: a first redistribution layer structure having a first surface and a second surface opposite thereto; a first semiconductor die disposed on the first surface of the first RDL structure; a first molding compound disposed on the first surface of the first RDL structure and surrounding the first semiconductor die; and an inter-metal dielectric structure disposed on the first molding compound and the first semiconductor die, wherein the IMD structure comprises a dielectric layer and a conductive shielding layer covering the first semiconductor die; wherein the conductive shielding layer is disposed on and covers the entire upper surface of the dielectric layer and extends along the sidewalls of the dielectric layer, the first molding compound, and the first RDL structure to the second surface of the first RDL structure so that the sidewall of the semiconductor package structure is substantially covered by the conductive shielding layer; wherein the first semiconductor package further comprises a second semiconductor die disposed on the first surface of the first RDL structure, such that the first and second semiconductor dies (110, 210) are arranged side-by-side wherein the second semiconductor die is covered by the conductive shielding layer; wherein the first semiconductor package further comprises a plurality of first vias passing through the first molding compound and electrically coupled to the first RDL structure; characterized in that at least one of said first vias is coupled to the conductive shielding layer covering the first semiconductor die. a first redistribution layer structure having a first surface and a second surface opposite thereto; a first semiconductor die disposed on the first surface of the first RDL structure; a first molding compound disposed on the first surface of the first RDL structure and surrounding the first semiconductor die; and an inter-metal dielectric structure disposed on the first molding compound and the first semiconductor die, wherein the IMD structure comprises a dielectric layer and a conductive shielding layer covering the first semiconductor die; wherein the conductive shielding layer is disposed on and covers the entire upper surface of the dielectric layer and extends along the sidewalls of the dielectric layer, the first molding compound, and the first RDL structure to the second surface of the first RDL structure so that the sidewall of the semiconductor package structure is substantially covered by the conductive shielding layer; wherein the first semiconductor package further comprises a second semiconductor die disposed on the first surface of the first RDL structure, such that the first and second semiconductor dies (110, 210) are arranged side-by-side wherein the second semiconductor die is covered by the conductive shielding layer; wherein the first semiconductor package further comprises a plurality of first vias passing through the first molding compound and electrically coupled to the first RDL structure; characterized in that at least one of said first vias is coupled to the conductive shielding layer covering the first semiconductor die.