A layout method applied to a connector is provided. The connector is electrically connected between a flexible printed circuit (FPC) and a printed circuit board (PCB). The FPC includes M pairs of differential lines and X shield lines. The PCB includes M pairs of differential lines and Z shield lines. The layout method includes following steps. Firstly, M pairs of conductive lines are disposed on the connector. The M conductive lines are correspondingly electrically connected to the M differential lines of the FPC and the M differential lines of the PCB. Then; Y conductive lines are disposed on the connector, wherein Y is smaller than X. Furthermore, at least one of the Y conductive lines is electrically connected to at least one of the X shield lines and at least one of the Z shield lines.