In addition to analyses of bulk-rock major and minor element composition of mantle peridotite xenoliths in Cenozoic basalt at Wangqing, Jilin Province, we further analyzed the major and trace elements of minerals, and discussed the partial melting and metasomatism of SCLM at the joint area between North Cbina Craton and Mongolia-Hinggan Orogen. Mineral compositions as evidenced by Fo in olivine, Mg# and Cr# in both elinopyroxene and spinel suggest that the SCLM beneath Wangqing is relatively fertile. Simulated calculation of trace elements for diopside in mantle peridotites proves that the SCLM beneath Wangqing has undergone 1 %- 3% partial melting followed by silicate melt metasomatism. These mantle features are similar to Cenozoic SCI.M beneath other areas of eastern China. Our results suggest that the transformation of SCLM nature was realized through delamination under a "multiple" convergent plate tectonic domain.