By the analysis of the characteristics of ice run and causes of ice run disaster in the Inner Mongolia section of the Yellow River, it points out that the precipitation status of the upper and middle reaches of the Yellow River, the freezing status in winter and the melting speed in spring have a close relation with the ice run disaster.Based on the innate laws of ice run disaster,the ice run disaster index is obtained.Meanwhile,it points out the critical temperature index of freezing of the Yellow River and the way of forcasting the date of breakup of the ice in the Yellow River.