Abstract: Major elements, trace elements, REE and Nd isotopic geochemistry of the Cenozoic dacites from Lianghe-Luxi area, western Yunnan Province, were studied in this paper, and the results show that the dacites are enriched in light REE, large-ion lithophile elements and Pb and depleted in Nb, Ta, Sr, P, Ti and heavy REE, with negative Eu anomaly and positive Pb anomaly. These rocks have εNd(0) values from -10.3 to -8.72 and Nd isotopic model ages (tDM) from1.2 to 1.4Ga. It is suggested that the Lianghe-Luxi Cenozoic dacites were derived dominantly by partial melting of crystalline basement rock mixed in different degrees with melts of coeval mantle-derived basaltic magma.