A circuit substrate includes a base substrate, a plurality of conductive vias, a first redistribution circuit structure, a second redistribution circuit structure and a semiconductor die. The plurality of conductive vias penetrate through the base substrate. The first redistribution circuit structure is located on the base substrate and connected to the plurality of conductive vias. The second redistribution circuit structure is located over the base substrate and electrically connected to the plurality of conductive vias, where the second redistribution circuit structure includes a plurality of conductive blocks, and at least one of the plurality of conductive blocks is electrically connected to two or more than two of the plurality of conductive vias, and where the base substrate is located between the first redistribution circuit structure and the second redistribution circuit structure. The semiconductor die is located over the base substrate and laterally arranged next to the second redistribution circuit structure.