This paper discusses the classification, distribution, and mineralogical characteristics of two series of granitic rocks: the magnetite-series and the ilmenite-series. The magnetite-series granitoids are characterized by the presence of magnetite (0.1-2 vol.%), ilmenite, hematite, pyrite, sphene, epidote, and high ferric/ferrous biotite, while the ilmenite-series granitoids are characterized by the presence of very small amounts of ilmenite (less than 0.1 vol.%), pyrrhotite, graphite, muscovite, low ferric/ferrous biotite, and other accessory minerals. The mineral assemblages suggest that the magnetite-series granitoids formed under higher oxygen fugacity conditions compared to the ilmenite-series granitoids. The magnetite-series granitoids are believed to have originated in deep regions (upper mantle and lowest crust) without interacting with carbon-bearing materials, whereas the ilmenite-series granitoids formed in the middle to lower continental crust and interacted with C-bearing metamorphic and sedimentary rocks at various stages of their igneous history. The distribution of these two series is influenced by the tectonic setting and the presence of carbonaceous materials. The study also discusses the genetic implications for the formation of granitoids and associated ore deposits, such as porphyry copper-molybdenum deposits and greisen-type tin-wolframite deposits. The lack of porphyry copper deposits in the Mesozoic orogeny belts in East Asia is attributed to the scarcity of magnetite-series granitoids in these terranes.This paper discusses the classification, distribution, and mineralogical characteristics of two series of granitic rocks: the magnetite-series and the ilmenite-series. The magnetite-series granitoids are characterized by the presence of magnetite (0.1-2 vol.%), ilmenite, hematite, pyrite, sphene, epidote, and high ferric/ferrous biotite, while the ilmenite-series granitoids are characterized by the presence of very small amounts of ilmenite (less than 0.1 vol.%), pyrrhotite, graphite, muscovite, low ferric/ferrous biotite, and other accessory minerals. The mineral assemblages suggest that the magnetite-series granitoids formed under higher oxygen fugacity conditions compared to the ilmenite-series granitoids. The magnetite-series granitoids are believed to have originated in deep regions (upper mantle and lowest crust) without interacting with carbon-bearing materials, whereas the ilmenite-series granitoids formed in the middle to lower continental crust and interacted with C-bearing metamorphic and sedimentary rocks at various stages of their igneous history. The distribution of these two series is influenced by the tectonic setting and the presence of carbonaceous materials. The study also discusses the genetic implications for the formation of granitoids and associated ore deposits, such as porphyry copper-molybdenum deposits and greisen-type tin-wolframite deposits. The lack of porphyry copper deposits in the Mesozoic orogeny belts in East Asia is attributed to the scarcity of magnetite-series granitoids in these terranes.