The invention provides a printed circuit board for mobile platforms. An exemplary embodiment of the printed circuit board for mobile platforms includes a core substrate having a first side. A ground plane covers the first side. A first insulating layer covers the ground plane. A plurality of first signal traces and a plurality of first ground traces are alternatively arranged on the first insulating layer. A second insulating layer connects to the first insulating layer. A plurality of second signal traces separated from each other is disposed on the second insulating layer, wherein the second signal traces are disposed directly on spaces between the first signal traces and the first ground traces adjacent thereto.