A semiconductor package with a heat dissipating device and a fabrication method of the semiconductor package are provided. A chip is mounted on a substrate. The heat dissipating device is mounted on the chip, and includes an accommodating room, and a first opening and a second opening that communicate with the accommodating room. An encapsulant is formed between the heat dissipating device and the substrate to encapsulate the chip. A cutting process is performed to remove a non-electrical part of structure and expose the first and second openings from the encapsulant. A cooling fluid is received in the accommodating room to absorb and dissipate heat produced by the chip. The heat dissipating device covers the encapsulant and the chip to provide a maximum heat transfer area for the semiconductor package.