Abstract: The Shaliuhe tungsten-tin orefield in Qinghai Province, tectonically belonging to the eastern margin of the Caledonian synclinorium fold belt in northern Qaidam Basin, is broadly intruded by Indosinian rocks. With discussion on the composition, lithology and petrochemistry of intrusive rocks, this paper analyzes the relationship between the rocks and the W-Sn metallogenesis. The result shows that the ore-forming rock in the orefield is dominated by biotite monzogranite, belonging to S-type of weak alkaline-peralkaline silica-aluminum supersaturated granite, with various kinds of accessory minerals. The Pb, Zn, W and Sn contents in the rock are 1.5-3.3 times higher than the world average values of granite, suggesting that the intrusive rock in the area is the material source for W-Sn mineralization. The granite is analyzed with the approaches of (K+Na)-Si correlation diagram, SiO₂-(CaO+MgO+FeO)-(Na₂O+K₂O+Al₂O₃) phase diagram and differentiation index histogram. It is concluded that the porphyraceous biotite monzogranite in the orefield shows great similarity to the W-Sn ore-forming rocks both in China and abroad in lithology, petrochemistry, composition and forming time, to be a favorable metallogenic parent rock.