A package structure is provided. The package structure includes a semiconductor die over a redistribution structure, bonding elements below the redistribution structure, and an underfill layer surrounding the bonding elements and the redistribution structure. The semiconductor die has a rectangular profile in a plan view. A pitch of the bonding elements is defined as the sum of a diameter of the bonding elements and a spacing between neighboring two of the bonding elements. A first circular area of the redistribution structure is entirely covered and in direct contact with the underfill layer. The center of the first circular area is aligned with a first corner of the rectangular profile of the semiconductor die. A diameter of the first circular area is greater than twice the pitch of the bonding elements.