Jinduicheng granitoids and the it related porphyry Mo deposits lie within the Henan-Shanxi faulted-upwarping area along the southern edge of the Sino-Korean paraplatform. The Yenshanian granitoids (124 to 130 Ma) consist of Laoneushan biotite monzonitic granite batholith and Shijiawan-Jinduicheng granite porphyries.The Laoneushan granite body intruded into gneiss of Archean Taihua Group and meta-spilite of Proterozoic Xionger Group, with an exposed area of some 440 km~2. The Shijiawan granite porphyry intruded into meta-spilite of Xionger Group and metamorphic quartz sandstone as well as quartzite of Gashanhe Formation. The Jinduicheng granite porphyry intruded into meta-spilite of Xionger Group. Those granite porphyries are all less than 1 km~2 in size. Mineralogical studies show that not only can the structure state and composition of plagioclase and K-Na-feldspar provide the information on origin and evolution of granitoids, but these minerals themselves might act as Mo-carrier as well. Along with wide and strong hydrothermal alterations of post-granite porphyry period, Mo released from the Mo-carrier was superimposed on the original Mo stockworks, forming high-grade ores of granite type. In addition, the F-, HREE-rich biotite with distinct negative Eu anomaly can be taken as a useful indicator mineral for Mo ore prospecting in granitoid areas.