Abstract:This paper demonstrates the basic situation of two mordern volcanoes,La oh eishan and Huoshaoshan,in the Wudalianchi volcanic group,and the distribution and chara cterestics of pumicecinder fragments and lava flows.On this basis,the authors propose that:① the Laoheishan volcano is not a monogentic volcano;② vol canic eruption is characterized by fissure eruption at first and then centralv ent eruption;③ eruption of pumicecinder fragments and magma eruption happened at the same time;④ compared with the Icelandic Laki Volcano,Italy Strombolian Volcano and American Hawaiian Volcanoes;it is pointed out that the eruption type of the Laoheishan volcano in Wu dalianchi has a new type of volcanic eruption, which was named "the Wudalianchi Laoheishan Type ".