Several types of granites are distributed in Kalamaili area of East Junggar, Xinjiang, which constitutes an important tin metallogenic zone. The Belekuduke granite intrusion is situated in the central of the tin metallogenic zone, which consists of biotite syenite granite and biotite monzogranite, High-precision LA-ICP-MS zircon U-Pb dating has revealed that the ore-hosting biotite syenite granite in the Belekuduke granite intrusion were formed at 283±2Ma，MSWD=0.14(95% conf), the time belongs to the Early Permian, it coincides with the age(330~265Ma) of post-collisional magma activity around the east Junggar area. On the basis of the preliminary petrological and geochemical study reveal that the intrusion characterized by high silicon (SiO2=75.25%~76.67%), low aluminium (Al2O3=11.91%~12.86%), depleted magnesium and calcium (MgO=0.02%~0.18%, CaO=0.39%~0.89%) and abundant alkali (Na2O+K2O=8.08%~8.97%), K2O>Na2O, NK/A=0.86~0.95(the average is 0.92), A/NCK=0.97~1.02, the rock enrichment of LILE(such as Rb and K) and HFSE(such as Zr and Hf), defected of Ba、Nb and Sr, have lowest δEu(δEu=0.01~0.11), the value of the FeOt/MgO(FeOt/MgO=12.71~84.51, the average is 34.55)and 10000Ga/Al(2.97~4.20)is high, so as to the HFSE (Zr+Nb+Ce+Y=191.8×10-6~353.3×10-6), that different from I- and S-type, shows that biotite granites are actually typical aluminous A-type granite. On the basis of reseaching geochronology and geochemical, the Belekuduke aluminous A-type granite formed by the basic magma from mantle and acid one from crust mixing, is the recorder of continental crust growth that by post-collision mantle magma underplating in east Junggar. The content Sn(6.0×10-6~19.5×10-6，respectively is 80.0×10-6) is high in the Belekuduke aluminous A-type granite, the intrusion is direct matrix of the tin deposit fluid, the tin-bearing fluid formed the Belekuduke tin deposit, the tin deposit and aluminous A-type granite are formed in the same geology incident in east Junggar.