Provided is a circuit board structure including a substrate, a loop-wrapping ground layer, an insulating structure, a first build-up layer, a top wiring layer, a bottom wiring layer, a first conductive via, and a plurality of second conductive vias. The aforementioned structure defines a signal transmitting structure. An equivalent circuit of the signal transmitting structure at least includes a first equivalent circuit, a second equivalent circuit, a third equivalent circuit and a fourth equivalent circuit, which correspond to different uniform transmitting sections respectively. The first equivalent circuit, the second equivalent circuit, the third equivalent circuit and the fourth equivalent circuit are connected in series with each other according to an ABCD transmission matrix series connection principle.