The two-mica syenogranite in the Keyinblak Cu-Zn deposit area is located in Chonghuer sedimentary volcanic basin near the north of Erqis tectonic belt in the southern margin of Altay. The postmagmatic hydrothermalism is closely related to the deposit. The age of (278.6±3.5) Ma (MSDW=2.8) for the pluton by LA-MC-ICP-MS attributes to late Hercynian. Synthesizing the former study, the authors suggest that the two-Mica granite has formed in post-collisional processes and may be related to the local large scale shear event, probably as a result of part melting of metasedimentary rocks in Kangbutiebao Formation due to the underplating of magma from mantle source during the late period of crustal extension.