A rear auxiliary riding board (2) is provided for a baby carriage, which can be detachably mounted on the rear side of the baby carriage, allowing a young child to stand thereon. The rear auxiliary riding board includes a platform (21) on which a young child can stand; at least one wheel (211) mounted on the bottom side of the platform; a coupling device (22) for coupling the rear auxiliary riding board to one side of the baby carriage, the coupling device including at least one clasp (221) which can clasp on one horizontal bar on the baby carriage; and a linking device (23) having a vertical portion (23A) and a horizontal portion (23B), the vertical portion being formed with a plurality of holes which can be selected for fastening the linking device to the coupling device (22) by using a first fastening means, and the horizontal portion being linked to the platform by means of a second fastening means. The linking device (23) can be affixed to the coupling (22) device by means of a bolt-and-nut method through the hole in the frame of the coupling device and at least one of the plurality of holes so selected in the vertical portion of the linking device. The provision of the plurality of vertically lined-up holes formed in the vertical portion of the linking device allows the rear auxiliary riding board to be coupled to any type of baby carriages with rear horizontal bars at different elevations from the ground.