Mesozoic granodiorites occurring in southwestern Fujian, whose ages are 183~162 Ma and 108~106 Ma respectively, belong to high_K calc-alkaline series of intraplate with K2O +Na2O>6.0%. Early and late granodiorites are enriched in Na2O and K2O respectively. The chondrite-normalized REE patterns are characterized by LREE enrichment with weak negative Eu anomalies (δEu=0.80~0.86). In the primitive mantle-normalized spidergrams, they are enriched in LILE and LREE with significant Nb, Ta, Ti, Y depletion and possess the geochemical features of calc-alkaline rocks in island arc or acive continental margin. The geochemical characteristics of the two types of Mesozoic granodiorites suggest that their source region may be an enriched lithosphere mantle affected and altered by ancient subduction materials or source mixing between asthenosphere-derived basalts and crust materials. Perhaps there have occurred many times of lithospheric extension and thinning since Early Mesozoic in southwestern Fujian. The granodiorites were mixed between partial melts of middle/lower crust-derived materials and mantle magma. With the increasing extension, the mantle components in Late Mesozoic granodiorites gradually grow.