The Beilekuduke biotite granites in the study area have long been thought to be of S-type. Nevertheless, the preliminary research conducted by the authors shows that biotite granites are actually typical aluminous A-type granites, which have the following characteristics: enriched silica (SiO2=75.25%～76.67%) and alkali (Na2O+K2O=8.08%～8.97%), low magnesium (MgO=0.02%～0.18%) and calcium (CaO =0.39%～0.89%), obvious variation of oxidation index (W=0.02～0.12), high FeOT/MgO ratio (12.71～84.51, 34.55 on average). K2O＞Na2O, NK/A=0.86～0.95 (0.92 on average), A/CNK=0.97～1.02 (higher than 0.95), thus belonging to sub-aluminous—ultra-aluminous calc-alkali—weak-alkali rocks. In trace element and REE characteristics, the rocks are enriched in HFSE (such as Ga, Zr and Hf) and depleted in Ba, Nb and Sr. 10 000 Ga/Al ratios (2.97～4.20) are exclusively higher than the lower limit value of the A-type granites (2.6), obvious higher than average values of I-, S-type granites (2.1 and 2.28, respectively). In Zr, Ce, Nb versus 10 000 Ga/[CM(46]Al and FeOT/MgO versus (Zr+Nb+Ce+Y), SiO2 diagrams, the samples fall into the area of A-type granites, and are obviously different from things of I, S-type granites. The above characteristics show that Beilekuduke biotite granites are very similar to such typical aluminous A-type granites in the world as aluminous A-type granites in the coastal area of Fujian Province, in west and east Jungaar and in the Lachlan fold belt of southeastern Australia. In Nb-Y-Ce, R1-Ga/Al and R1-R2 tectonic diagrams, they belong to post-orogenic granites. The determination of the Beilekuduke typical aluminous A-type granites not only has geological significance in the study of the crust material composition and tectonic evolution in Kalamaili area but also opens up a new orientation in looking for tin resources related to aluminous A-type granites in northern Xinjiang.