A wheel speed sensor mounting structure comprising: a fork which rotatably supports a wheel; a brake disc which is mounted on a side surface of the wheel in an integrally rotatable manner and which includes a braking portion to which braking is applied by a brake caliper; and a wheel speed sensor for detecting a rotational speed of the wheel, wherein the wheel speed sensor includes: a pulsar ring which is rotated integrally with the wheel; and a sensor body portion which is arranged close to an annular portion to be detected formed on the pulsar ring and generates pulse signals corresponding to a rotational speed of the pulsar ring, wherein the pulsar ring is mounted on a wheel side, and the sensor body portion is mounted on a fork side, wherein the pulsar ring mounting portion is fastened to the side surface of the wheel together with a brake disc mounting portion formed on the brake disc using a fastening member in a state where the pulsar ring mounting portion overlaps with the brake disc mounting portion, and the pulsar ring includes pulsar ring mounting portions which project in the radially outward direction from the portion to be detected, the structure includes a brake hose which extends upwardly from the brake caliper behind the fork, the brake caliper is arranged behind the fork the sensor body portion is arranged between the fork and the brake caliper, and a sensor cable is connected to the sensor body portion and extends upwardly from the sensor body portion along the fork; the structure being characterized in that a seat portion of the pulsar ring mounting portions which is fastened by the fastening member, and the portion to be detected are arranged on the same plane; and said sensor cable is supported by a clip which is mounted on a caliper bracket, is bent rearwardly from the clip, extends rearwardly after passing an area above the brake caliper and is further bent upwardly, toward an upper side of the vehicle together with the brake hose. a fork which rotatably supports a wheel; a brake disc which is mounted on a side surface of the wheel in an integrally rotatable manner and which includes a braking portion to which braking is applied by a brake caliper; and a wheel speed sensor for detecting a rotational speed of the wheel, wherein the wheel speed sensor includes: a pulsar ring which is rotated integrally with the wheel; and a sensor body portion which is arranged close to an annular portion to be detected formed on the pulsar ring and generates pulse signals corresponding to a rotational speed of the pulsar ring, wherein the pulsar ring is mounted on a wheel side, and the sensor body portion is mounted on a fork side, wherein the pulsar ring mounting portion is fastened to the side surface of the wheel together with a brake disc mounting portion formed on the brake disc using a fastening member in a state where the pulsar ring mounting portion overlaps with the brake disc mounting portion, and the pulsar ring includes pulsar ring mounting portions which project in the radially outward direction from the portion to be detected, the structure includes a brake hose which extends upwardly from the brake caliper behind the fork, the brake caliper is arranged behind the fork the sensor body portion is arranged between the fork and the brake caliper, and a sensor cable is connected to the sensor body portion and extends upwardly from the sensor body portion along the fork; the structure being characterized in that a seat portion of the pulsar ring mounting portions which is fastened by the fastening member, and the portion to be detected are arranged on the same plane; and said sensor cable is supported by a clip which is mounted on a caliper bracket, is bent rearwardly from the clip, extends rearwardly after passing an area above the brake caliper and is further bent upwardly, toward an upper side of the vehicle together with the brake hose.