A package structure includes a plurality of stacked die units and an insulating encapsulant. The plurality of stacked die units is stacked on top of one another, where each of the plurality of stacked die units include a first semiconductor die, a first bonding chip. The first semiconductor die has a plurality of first bonding pads. The first bonding chip is stacked on the first semiconductor die and has a plurality of first bonding structure. The plurality of first bonding structures is bonded to the plurality of first bonding pads through hybrid bonding. The insulating encapsulant is encapsulating the plurality of stacked die units.