A gear-rolling apparatus includes two gear units and a base. Each gear unit has a rolling portion, a rolling shaft extends from the rolling portion, a clicking column and two location columns extend from edges of a free end of the rolling shaft along an axle direction of the rolling shaft. The clicking column and the two location columns are spaced out from each other to form three grooves therebetween, a clicking clasp extends inward from the top of the clicking column. The clicking clasp has an inclined inner surface which inclines inward from top to bottom. The two rolling shafts are inserted into the hole of the base, the clicking column of one of the rolling shafts mates the groove opened between the location columns of the other rolling shaft, the location columns of one of the rolling shafts mate the grooves opened between the clicking column and the location columns of the other rolling shaft respectively, bottom surfaces of the two clicking clasps are against each other.