A semiconductor structure is provided. The semiconductor structure includes a semiconductor wafer and a test structure. The semiconductor wafer has a substrate having a scribe line area, a first die area and a second die area. The first die area and the second die area are separated by the scribe line area extending along a first direction. The test structure is disposed in the scribe line area. The test structure includes a test device and a first test pad. The test device has a physical characteristic similar to a semiconductor device fabricated in the first die area or the second die area. The first test pad is electrically connected to the test device. A first distance between the first test pad and the first die area gradually increases from a center region to a peripheral region of the first test pad in the first direction.