Abstract: The formation and development of stress cracks of corn in the stages of drying,cooling and storing were observed respectively. Cracks originated on the crown of corn flank as a white asterisk spot,and then expanded to short crack, and to long crack. The numbers of cracks developed from single to double, to checked. Cracks on flanks were more than that on the front and the back respectively. When the cracks on the front and back formed,the state of cracks in kernels was in checked. Cracks that formed and developed in a short period of storing after drying were more than other stages.