Phlogopite-amphibole pyroxenite xenoliths within alkaline basic-ultrabasic aubvolcanic complex are composed of diopside, titanium-rich pargasite, high-titanium phlogopite, apatite and ilmenite, exhibiting threeling, cataclastic and kink-banded textures. Compared with original spinel lherzolite from eastern China, the xenoliths are enriched in TiO2, Fe2O3, CaO,Na2O, K2O, with an apparent depletion in MgO. Chondrite-normalized REE patterns and primordial mantle normalized trace elements data show that they are enriched in REE (especially LREE) and incompatible trace elements. Petrographic, mineralogical and chemical characteristics indicate that the xenoliths are metasomatized mantle xenoliths, which represent the anomalous mantle of early Palaeozoic rift in northern Daba Mountain. Mantle plume was the most probable agent for producing the xenoliths. with the ascending of the mantle plume, major metasomatic agents changed from melts to fluids.