There are abundant Paleozoic granites in China's Altay orogenic belt, which played an important role in the tectonic evolution. In this study, LA-ICP-MS zircon U-Pb dating yielded the ²⁰⁶Pb/²³⁸U ages of 407±3 Ma and 491±3 Ma for the gneissic granite and gneissic tonalite of the Aobaote pluton in Qinghe area respectively, suggesting early Devonian and terminal Cambrian period. The gneissic granite is of calc-alkaline or alkali-calc nature, and belongs to magnesian granite. It is metaluminous-slightly peraluminous with the A/CNK values being 0.98~1.08 and normative corundum values being less than 1. And there are high Y values of 27.2×10^-6~40.5×10^-6 and Th values of 10.2×10^-6~27.0×10^-6, which increase with increasing Rb. The above characteristics indicate that the gneissic granite belongs to I-type granite. There are low SiO₂ values of 60.28%~64.01% for the gneissic tonalite, and its A/CNK values show that its protolith was metaluminous-slightly peraluminous. Together with its trace element characteristics, the authors hold that the gneissic tonalite is characterized by I-type granite. Synthetic analysis shows that the gneissic granite and gneissic tonalite were formed by the subduction.