Abstract: Ice dams often occur in the upper reaches of the main stream of the Heilongjiang River during the ice flood period. In order to predict the date of ice breakup and illuminate the flood process caused by ice dams in the Mohe reach of the Heilongjiang River, an ice dam prediction model was established based on BP neural network through analyzing hydrometeorological data from 1960 to 2010 in the Mohe reach in order to predict the occurrence of ice dams and the date of ice breakup from 2011 to 2015 compared with the actual situation during the period. The research result indicates that the model has high predictive accuracy. Moreover, the dates of ice breakup and temperature normalization have been stabilized based on the analysis of the 27-years temperature data, and ice breakup would occur in the Mohe reach 15 days later after the temperature normalization. In addition, the dates of ice breakup from 2011 to 2015 were predicted, and the maximum error was 3 days. According to the hydrological information forecast specification, this prediction was a first-class prediction and the prediction results were qualified.