Both the Laohei Mountain and Huoshao Mountain (extinct or dormant volcanoes） belong to the wellknown Wudalianchi volcano swarm, Wudalianchi World Geopark, located in Dedu County, Heilongjiang Province.The debris avalanche occurred in Laohei and Huoshao volcanoes formed hummocky deposit. Several decades hummocks are distributed in the west, east and southwest of the Laohei Mountain and there are several decades hummocks in the north and northeast of the Huoshao Mountain. The largest hummock is about 17m in height and the base diameter is over 50m long. The largest distance of the hummock from the volcano is as far as 2km. These hummocks composed of large debris avalanche blocks should be the block facies of the debris avalanche deposits and the blocks consist of greypurple basaltic volcanic agglomerate and volcanic breccia that as same as that of the rocks exposed in the base of the cones of Laohei Mountain and Huoshao Mountain, which indicate that these deposit resulted from the avalanche event happened in the two volcanoes. Most of the debris avalanche blocks were shattered strongly, but is partial preservation of primary edifice stratigraphy occasionally. These blocks were highly fractured and often with small fauts. During period of 1720~1721 AD the Laohei Mountain volcano formed in the Middle Pleistocene (0.16Ma) and Huoshao Mountain volcano erupted again. The eruption model is: debrisavalanche (debrisavalanche deposits and hummocky terrain)—lava flows (aalava and pahoehoelava)— Strombolian column (scoria cones of both Laohei Mountain and Huoshao Mountain and tepra sheets around the cones). Hazards derived from the avalanche themselves, as well as from associated pyroclastic flow and lahar that exceed damage beyond the debris avalanche deposits have been discussed.