Green-pyroxenite xenoliths(inciuding green- pyroxene xenocrysts)that occur in the Early paleozoic alkaline mafic-ultramafic subvolcanic lamproph-yric complex within Langao County on the northern margin of Yantze plate might be classified into threo groups according to their potrotocrraphlcal facles and geochemical composition-All the green- pyroxenos in this area are green or pale,green colored,and can be easily distinguished from colorless pyroxenes.According to geochomical characterisics,most green-pyroxenes can be aseigned to Ca-Mg-Fe pyroenes rich in Na,while a fetw might be regarded as aeglrine-augite.Green-pyroxenes in the first group are rich in Mg and Ca but defi-cient in Fe and Na,while those in the second and the third group are rich in Fe and Na but deficient in Mg and Ca. Goochemical characteristics of all groen-pyroxenes change regularly,indicating that all green-pyroxenes crystal-lized from the same magma but at different depths:those in the socond group were formed under higher pressure than those in the first and the third group,Compared with those in the other two groups,the green-pyroxenes in the first group were crystallized at the later stage of the samo magmati evo-lutionary process. A study of the green-pyroxenite xenoliths shows that there existed ano-ther kind of magma-peralkaline basic magma derived from the small degree of partial melting of the metasomatized mantle at the early stage of the conti-nental rifting in Early Paleozoic,An investigation into peralkaline basic ma-gma would reveal more information about the tectonic movement of the conti-nental rift in North Daba Mountain and the evolution of lithosphere in South Qinling Mouptains.