An interconnection structure for a package is disclosed. The interconnection structure includes a substrate body having a conductive portion formed on a surface thereof; a first photosensitive dielectric layer formed on the surface of the substrate body and having a via for exposing the conductive potion; a conductive via formed in the via; a second photosensitive dielectric layer formed on the first photosensitive dielectric layer and having a opening for exposing the conductive via and a portion of the first photosensitive dielectric layer; and a conductive trace layer formed in the opening of the second photosensitive dielectric layer so as to be electrically connected to the conductive portion through the conductive via, thereby simplifying the fabrication process and reducing the fabrication cost and time.