Abstract: A rack is made up of a plurality of support rods and locating devices for locating the support rods. Each of the locating devices are composed of a hollow tubular body, an elastic ring, and a control piece. The tubular body is provided respectively at both longitudinal ends thereof with outer threads and an outer tapered circular edge. The control piece is tubular in shape and is provided with a center through hole and an inner tapered circular edge. The elastic ring is disposed between the outer tapered circular edge of the tubular body and the inner tapered circular edge of the control piece. The support rod is received in the hollow interior of the tubular body and the center through hole of the control piece such that the outer wall of the support rod is pressed against firmly by the elastic ring at the time when the control piece is so turned as to cause the inner tapered circular edge thereof to press against the elastic ring.