The present invention discloses a structure of package comprising: a substrate with a die receiving through hole, a connecting through hole structure and a first contact pad; a die disposed within the die receiving through hole; a surrounding material formed under the die and filled in the gap between the die and sidewall of the die receiving though hole; a dielectric layer formed on the die and the substrate; a re-distribution layer (RDL) formed on the dielectric layer and coupled to the first contact pad; a protection layer formed over the RDL; and a second contact pad formed at the lower surface of the substrate and under the connecting through hole structure.