A manufacturing method of a package structure is provided. A metal substrate is provided. The metal substrate has a first surface where a first seed layer is formed. A patterned insulating layer is formed on the first seed layer and exposes a portion of the first seed layer. A patterned circuit layer is formed on the exposed portion of the first seed layer and covers a portion of the patterned insulating layer. A chip-bonding process is performed to electrically connect a chip to the patterned circuit layer. An encapsulant encapsulating the chip and the patterned circuit layer and covering a portion of the pattered insulating layer is formed. The metal substrate and the first seed layer are removed to expose a bottom surface of the patterned insulating layer and a lower surface of the patterned circuit layer. Solder balls are formed on the lower surface of the patterned circuit layer.