Rotation device is configured at the bottom of the body of a diaper changer so that the diaper changer is capable of rotating horizontally relative to the playard frame via the rotation device when mounting thereon. The rotation device includes a rotator and a supporter where the rotator connects to the body and mounts on the supporter for allowing the body to rotate relative to the supporter. The supporter is further configured at one side of the playard frame. The body can also be rotatably mounted on the playard frame by mounted the rotator directly into a shafting hole on the playard frame. With the rotation device, the diaper changer can be selectively set in a first using status for changing a baby's diaper or a second using status for allowing a babysitter for easy holding the baby up.