The authors collected and studied about 500 samples of major, 120 samples of trace arid 135 samples of rare earth elements of the volcanic rocks from the Northern Qinling Mountains and the southern margin of the North China platform .The volcanic rocks of the Xiong'er Group and the Dahongkou Formation areB-type of volcanics series, being the products of the contamination of mantle-derived mafic magma with crust-derived silice- ous magmas in the magma chambers of crust, with, continental rift tectonic settings. The metatholeiite formations of the Kuanping Group and the Qinling Group belong to A-type volcanics series, with mantle-derived magma genesis and sea trough tectonio settings.The spilite-keratophyre formations of the Erlangping Group and the Danfeng Group are C+A-type and C- type volcanics series, being the. mixing products of the magma from the lower crustal bottom and that from hot mantle diapirs at crust-mantle transitional zones, with sea basin tectonic settings.