A carrier for transmitting a high frequency signal and a carrier layout method thereof are provided. The carrier includes a substrate, conducting wires and reference planes both formed on the substrate. The carrier layout method includes defining impedance and thickness of the carrier according to the high frequency signal and defining layout parameters according to the impedance and the thickness. The layout parameters include a conducting layer formed on the conducting wires, a coplanar waveguide encompasses both the reference planes and the conducting wires as a part thereof, roughness portions formed on the conducting wires, recessed portions formed on the conducting wires, and the substrate being a high loss tangent substrate. The layout is performed according to the layout parameters defined thereabove, so as to increase loss of the high frequency signal in transmission.