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 pumicecinder 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 centralv ent eruption;③ eruption of pumicecinder 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 ".