Abstract: Disclosed are a balancing apparatus for a grinding stone to automatically adjust the balance of the grinding stone during the rotation of the grinding stone and a wheel grinder having the balancing apparatus. The balancing apparatus has a flange having a ring-shaped weight groove, a weight member received in the weight groove and a fluid filled in the weight groove. The weight groove is covered with cover. When the grinding stone rotates at high speed, the balance of the grinding stone is automatically adjusted by means of the weight member, thereby rapidly accomplishing the balance adjustment of the grinding stone. In addition, separate balancing process is not demanded after the dressing process due to the abrasion of the grinding stone.