Abstract: A fabrication method of a stacked package structure is provided, which includes the steps of: providing a substrate having at least a semiconductor device disposed thereon; and disposing a semiconductor package on the substrate through a plurality of conductive elements such that the semiconductor device is located between the substrate and the semiconductor package, and forming an encapsulant between the substrate and the semiconductor package to encapsulate the semiconductor device. The encapsulant can be formed on the semiconductor package first and then laminated on the substrate to encapsulate the semiconductor device, or alternatively the encapsulant can be filled between the substrate and the semiconductor package driven by a capillary force after the semiconductor package is disposed on the substrate. Therefore, the present invention alleviates pressure and temperature effects on the package to prevent warpage of the substrate and facilitate fabrication of multi-layer stacked package structures.