A skateboard is provided which includes a front board and a rear board that are connected at a predetermined distance and casters fixed to the bottoms of the boards, in which a hollow cover body is fitted in assembly holes and of housings and formed beneath the bottoms of the front board and the rear board, a first propeller shaft fitted in the assembly hole at the front board and a second propeller shaft fitted in the assembly board at the rear board are inserted in the hollow cover body in contact with each other by cam-shaped joint portions, and the first and second propeller shafts horizontally and elastically expand/contract in rolling motion of the front board and the rear board.