A chip package structure and a method for forming a chip package are provided. The chip package structure includes a first package which includes at least a semiconductor die, a dielectric structure surrounding the semiconductor die, and a plurality of conductive structures penetrating through the dielectric structure and surrounding the semiconductor die. The package structure also includes an interposer substrate over the first package and a plurality of conductive features in or over the interposer substrate. The package structure further includes a second package over the interposer substrate, and the first package electrically couples the second package through the conductive structures and the conductive features.