Located in the interior of South China, the Qin-Hang (Qinzhou Bay to Hangzhou Bay) metallogenic belt was formed by the collision between the Yangtze craton and the Cathaysian block in late Neoproterozoic. Most ore deposits in the belt were formed in Mesozoic although different types of deposits occurred in different geological periods. Studies show that Mesozoic rock-forming and ore-forming processes could be subdivided two categories, i.e., Mid-Jurassic (180～170 Ma) porphyry-skarn-vein Cu polymetallic deposits and related granodiorites, and Late Jurassic (160～150 Ma) greisen-quartz vein-skarn W-Sn polymetallic deposits and related granites. In this paper, these two kinds of granitic source rocks were compared with each other in such aspects as spatial-temporal distribution, chronology, geochemical, Sr-Nd isotopic characteristics and tectonic settings. The former was derived locally from the remelting of subducted ancient Pacific plate along the Qin-Hang fault zone, whereas the latter was resulted from subducted plate windows in the central part of South China in a continental crustal extension and thinning setting. Abundant mantle materials were involved during the two types of rock-froming and ore-forming processes; nevertheless, less mantle materials were involved in the formation of Late Jurassic granitoids related to W-Sn deposits.