Abstract: A rear cover of a dartboard and a noise attenuation structure thereof includes: a rear cover, a shock and sound attenuation pad and a scoring board. The rear cover includes a plurality of reinforced ribs with a zigzag shape, every two reinforced ribs defines a resonant space. The shock and sound absorbing pad is provided with a plurality of grooves, every two said grooves define a stuffing portion, the reinforced ribs are disposed in the grooves, and the stuffing portions are stuffed in the resonant spaces, so as to reduce the resonant box. The zigzag reinforced ribs make it difficult for the resonance to be produced in the resonant spaces, and the stuffing portions stuffed in the resonant spaces further prevent the occurrence of resonance.