The Boziguoer A-type granitoids in Baicheng County of Xinjiang are ore-bearing rocks with abundant useful elements such as Nb, Ta and Zr. The petrological and mineralogical characteristics of the A-type granitoids were investigated on the basis of observation under polarized microscope, chemical analysis and detailed BSE images using EPMA, followed by the discussion on the p-T conditions of A-type magma generation and the tectonic setting. The results indicate that these A-type granitoids could be divided into three types, namely aegirine arfvedsonite quartz alkali feldspar syenite, aegirine arfvedsonite alkali feldspar granite and biotite alkali feldspar syenite. The major rock-forming minerals are quartz, albite, K-feldspar, aegirine, arfvedsonite and siderophyllite, whereas the accessory minerals include mainly zircon, pyrochlore, thorite, fluorite, monazite, bastnaesite and xenotime. The average temperatures of the magma are 832～839℃. A-type granitoids might have been formed in an anorogenic intraplate tectonic setting by which they generally show such features as high- temperature, anhydrous nature and low fugacity.