Abstract: An auxiliary rolling device of a skateboard comprises: a base at the bottom side of the skateboard; a brace, being mounted onto the base; a recession, being disposed on the brace; a shaft rack, being protruded from each of the sides of the recession, and a penetrating hole, being disposed each on the shaft rack, and a shaft passes through the penetrating holes such that the shaft is fixed into a position and both of its ends protrudes out of the shaft rack, and a wheel is mounted onto each end of the shaft. A roller wheel is sheathed into the middle section of the shaft, and the external diameter of the roller wheel is smaller than that of the wheel.