Research achievements on the estimation of loss of life caused by dam breaks are summarized in this paper, with consideration of the complexity of such estimation. Warning and evacuation processes were studied. Warning and evacuation models as well as a mortality estimation model were established to estimate the number of exposed people. The idea of dividing the hazard zones based on flood characteristics is proposed on the basis of historical data on dam breaks in China. Criteria for dividing the hazard zones and mortality functions were established, as were a method and estimation formulas for estimating the loss of life caused by dam breaks in China. An application shows that the proposed method and estimation formulas can objectively evaluate the loss of lives caused by dam breaks in China.