To provide a system for clocking a racehorse passing through a section which is inexpensive and yet hardly brings about impossibility of clocking.

An ID transmitter 1 for transmitting a radio wave (d) including an ID code is fitted to the back of the head of a jockey m, the radio wave (d) from the ID transmitter 1 can be transmitted up to a distance of ≥10m with directivity in the right and left directions perpendicular to the traveling direction of the racehorse, ID receivers 2 for receiving the radio wave (d) including the ID code are arranged in a start gate and goal gate in a predetermined section along a traveling course (s), and the racehorse passing through the section and corresponding to the ID code received by the ID receivers 2 is clocked by a clock device.