Abstract: There arethree large scale tungsten deposits in the western segment of North Qilian Mountains, Northwest China, including Taergou, Xiaoliugou and Xiliugoudeposits from west to east on space. They have their own characteristics in geological features, with totally different metallogenic conditions. After comparing geological characteristics of these tungsten deposits and analyzing their metallogenic conditions, these deposits were thought to be the production of Caledonian Period.The initial W was sourced from the proterozoic old strata, the quantity, occurrence state and size of tungsten ore body are strictly controlled by geological structure, and the tungsten concentrated and enriched to be form the ore bodies by magmatic hydrothermal process of acidic granite intrusion. The main mineralization was lasted from Middle Ordovicianto Ludlow Silurian. The Tergou and Xiaoliugou tungsten deposits are formed during the "plate subduction", while the Xiliugou tungsten deposit is formed in the "continent-continent collision". The western segment of North Qilian Mountains has a good background of tungsten mineralization and favorable conditions for mineralization.Due to the low degree of geological works had been done in the peripherals of these deposits, a great break through will be obtain when the geological works(the main exploration method will be drilling) can be carried out in their peripherals and deep parts.