The analysis on the basis of the hydrometeorological observation data in Heilongjiang Province shows that the spatialtemporal distribution characteristics of mountain torrents are in agreement with those of heavy rainfall. The rain amounts of 3 hours, 24 hours and 10 days before a mountain torrent are most crucial for the occurrence of mountain torrents. The climate conditions and excessive deforestation are closely related to the occurrence of mountain torrents. Since the 1980s, the climate in Heilongjiang has become warm, and the number of heavy rains has increased obviously. Based on the mechanisms of landslides, debris flows, and soil erosion, in combination with the characteristics of mountain torrents in Heilongjiang Province, the conceptual models, weight index, and grades for mountain torrents are presented.