A fabrication method of a package structure having at least an MEMS element is provided, including: preparing a wafer having electrical connection pads and the at least an MEMS element; disposing lids for covering the at least an MEMS element, the lids having a metal layer formed thereon; electrically connecting the electrical connection pads and the metal layer with bonding wires; forming an encapsulant for covering the lids, bonding wires, electrical connection pads and metal layer; removing portions of the encapsulant to separate the bonding wires each into first and second sub-bonding wires, wherein top ends of the first and second sub-bonding wires are exposed, the first sub-bonding wires electrically connecting to the electrical connection pads, and the second sub-bonding wires electrically connecting to the metal layer; forming metallic traces on the encapsulant for electrically connecting to the first sub-bonding wires; forming bumps on the metallic traces; and performing a singulation process.