The Middle Jurassic Tunmen Formation volcanic rocks in Hong Kong mainly consist of andesitic lava, tuff and tuff breccias intercalated with tuffaceous sands. Based on petrography, it is found that the Tunmen Formation volcanic rocks may be divided into andesitic-dacitic lava and explosion breccia of volcanic conduit facies, and tuff breccias of explosion airfall facies. By summarizing latest research results and comparing with similar volcanic rocks of other regions in the world, it is identified that volcanic conduit facies explosion breccia is existed and paleo-volcanic neck cluster is characterized by linear distribution in Kong Hong.