Abstract: World-class Au-Cu deposits are distributed along Middle Tianshan Mountains of Uzbekistan and Kyrgyzstan. Special attention should be paid to Au-Cu prospecting in China's Middle Tianshan and its northern and southern edges. Recently, a large Au-Cu deposit of Kateba'asu in Xinyuan County of Xinjiang was discovered by No.1 Geological Survey Party of Xinjiang Bureau of Geology and Mineral Exploration and Mining. The Kateba'asu Au-Cu deposit is located on the northern margin of the Middle Tianshan Mountains of Xinjiang, ~30km southeast of Xinyuan County. Gold-copper mineralization mainly occurs in the alteration zone of Carboniferous monzonitic granite intrusion. Au-Cu ore bodies are a few to several thousand meters long and several to dozens of meters thick, assume tabular and lenticular forms, and have average grades of gold 3.84g/t and copper 0.65%. The ore bodies in the upper part are mainly associated with gold mineralization and copper mineralization which increases with the depth. Ore minerals include pyrite and chalcopyrite, which are probably the main gold-bearing minerals. Gold-copper mineralization was closely related to the hydrothermal process after the emplacement of granite intrusions (e.g., monzonitic granite, alkali-feldspar granite, granodiorite). The Kateba'asu Au-Cu deposit possesses great economic value and also indicates the existence of high prospecting potential in the Middle Tianshan Mountains of west Xinjiang. The discovery of the Kateba'asu large Au-Cu deposit gives us an example of the new prospecting model, in which geological survey goes ahead and then guides the commercial exploration, thus finally realizing important breakthrough.