Abstract: The sub-continental lithospheric mantle (SCLM) under the eastern part of North China was thinned and the geochemical characteristics were replaced during Mesozoic and Cenozoic. The Mesozoic SCLM under eastern Yangtze block shows the similar procedure as that in North China craton. This paper reports the geochemical characteristics of Mesozoic volcanics, which will be helpful for understanding the characteristics of Yangtze SCLM and the timespace relationship of the replacement characteristics from Mesozoic to Cenozoic. The Luzhong volcanics, occurring in eastern part of China and belonging to Yangtze block, are a set of Late-Mesozoic alkali-rich shoshonitic rocks, which include trachybasalts-basaltic trachyandesite-trachyte. The Suangmiao group, part of the Luzhong set, was studied in detail in this paper. The volcanics were slightly contaminated by crust materials during the formation, and the elemental and isotopic compositions can well reflect their mantle source. The basaltic rocks are characterized by enriched Rb, K, Sr, Th and LREE, and depleted HFSEs. They also have enriched Sr-Nd isotopic compositions with (87Sr/86Sr)i = 0.7060~0.7063，εNd(t ) = -3.9~-6.2，(206Pb/204Pb)i = 17.788~18.125，(207Pb/204Pb)i = 15.511~5.546, (208Pb/204Pb)i = 37.735~38.184. These data suggest that the magma was partially melted from enriched mantle source, which was effected by lower crust materials within the source, and followed by crystal fractionation. The magma composition and mantle source characteristics of Luzhong volcanics imply the extension of lithospheric mantle and asthenosphere upwelling in the Late Mesozoic.