The present invention relates to a heel cushion structure for a sneaker capable of adjusting the characteristic of the sneaker flexibly. The main body of the heel cushion structure is provided with plural separable elastic elements, so that the wearer is able to selectively screw different functional separable elastic elements according to personal needs. Thus, the wearer can selectively use the elastic elements according to personal needs. The cushion effect of the heel cushion structure of the sneaker can be adjusted by changing the separable elastic elements. Thereby, the present invention is truly a heel cushion structure that can flexibly adjust the characteristics of the sneaker.