An abdomen exerciser includes a connecting element, a first roller, a second roller and a holding component. The connecting element includes two connectors and two roller bearings, each connector has a receiving groove, a plurality of locating pores and a plurality of limiting slots. The connectors are connected with the first roller and the second roller respectively. The holding component is received in the receiving grooves. The holding component includes a plurality of ball bearings and a plurality of limiting elements, the ball bearings are locked in the locating pores, the limiting elements are received in the limiting slots.