A package structure and method of forming the same are provided. The package structure includes a die, a TIV, an encapsulant, an adhesion promoter layer, a RDL structure and a conductive terminal. The TIV is laterally aside the die. The encapsulant laterally encapsulates the die and the TIV. The adhesion promoter layer is sandwiched between the TIV and the encapsulant. The RDL structure is electrically connected to the die and the TIV. The conductive terminal is electrically connected to the die through the RDL structure.