A package structure includes a first dielectric layer, a first semiconductor device, a first redistribution line, a second dielectric layer, a second semiconductor device, a second redistribution line, a first conductive feature, and a first molding material. The first semiconductor device is over the first dielectric layer. The first redistribution line is in the first dielectric layer and is electrically connected to the first semiconductor device. The second dielectric layer is over the first semiconductor device. The second semiconductor device is over the second dielectric layer. The second redistribution line is in the second dielectric layer and is electrically connected to the second semiconductor device. The first conductive feature electrically connects the first redistribution line and the second redistribution line. The first molding material molds the first semiconductor device and the first conductive feature.