The essence of A-type granitoids is the enrichment of iron and the depletion of magnesium, and the A-type granitoids mean the collage of the felsic igneous rocks formed under the reduced environment. The term "A-type granitoids" is purely descriptive, and has no petrogenetic implications. The origin of the common metaluminous and peraluminous A-type granitoids needs high geothermal gradient, whereas the low pressure is not the essential condition for generating these melts.