Abstract:A-type granites are silicon-, alkali-rich, water-poor granitoids, characterized geochemically by poor Al, Sr, Eu, Ba, Ti and P. A-type granites are formed under low pressure and high temperature conditions, and have no choice for source rocks. The essence of the A-type (or the Nanling type) granites lies in the melting of granitic magma under low pressure and their generation mainly in the tectonic setting of crustal extension and thinning. The several "A-type granites" abroad cited by Wang Yang et al. are actually mostly outside the category of A-type granites and were not formed under low pressure conditions.