With the continuous improvement of the isotopic and tracing technologies for dating rocks, geologists have gained increasingly deepened understanding of the mantle and the interaction between the crust and the mantle in the past twenty years. Correspondingly, the knowledge of the A-type granite has been continually renewed. At present, just like adakite, A-type granites have covered granitoids (including their extrusive rocks such as rhyolite and rhyoandesite). The identification of A-type granites depends increasingly upon their major and trace elements as well as their isotope characteristics. Although A-type granites have diverse sources and genetic models, their tectonic setting remains mainly dominated by the extensional system.