A manufacturing method of a package structure is provided. A seed layer is formed on a upper surface of a metal substrate. A patterned dry film layer is formed on a lower surface of the metal substrate and the seed layer. A portion of the seed layer is exposed by the patterned dry film layer. The patterned dry film layer is used as an electroplating mask to electroplate a circuit layer on the portion of the seed layer exposed by the patterned dry film layer. A chip is bonded to and electrically connected to the circuit layer. A molding compound is formed on the metal substrate. The molding compound encapsulates the chip, the circuit layer and the portion of the seed layer. A portion of the metal substrate and a portion of the seed layer are removed so as to expose a portion of the molding compound.