The Taishanmaio intrusion is situated in the western Henan province as a batholith, which is on the southern margin of the North China craton with an area of ca. 290 km2. Based on the contact relationship, it can be divided into three stages (from early to late): medium—coarse grained alkalifeldspar granite, fine—medium grained alkalifeldspar granite and alkalifeldspar granite porphyry, respectively. The SHRIMP UPb zircon dating for the primary medium—coarse grained alkalifeldspar granite yields an age of 115±2Ma, which is later than Nannihu granite porphyries and Wenyu, Huashan, Heyu granite batholiths in this area. All three stages of granites have similar mineralogy and geochemistry. They are composed of primary perthite, albite(An<10), quartz and a small quantity of biotite, with miarolitic structures, and they are metaluminous and slightly peraluminous (A/CNK=0.95～1.13) and characterized by high silica(70.63%～76.59%), alkali(8.23%～9.34%), FeO*/MgO(3.00～7.21) and low CaO(0.46%～1.18%) and MgO(0.15%～0.65%). They also have relatively higher REE (except for Eu) and high strength field elements such as Zr, Nb and Ta concentrations, but lower Sc, Cr, Co, Ni, Sr and Eu concentrations. In addition, they have relatively high Ga/Al ratios (2.7～3.6), characterizing Atype granite, neither I nor S types of granite. On the geochemical discrimination diagrams, they can be classified into A1 type, and formed during the lithospheric extensional movement.