Abstract: Study of petrology of quartz monzonites from Dashui area suggests that the Zhonggezhala,Zhongqu and Ge'erkuohe bodies are derived from a comagmatic region.Although their crystallization temperature of about 700℃~800℃ is exactly alike,the emplacement depth among them is very different,from 20km~22km of Zhonggezhala through 16km of Zhongqu to 8km~11km of Ge'erkuohe towards the east.Moreover,the later two bodies show a signature of subvolcanic rock.This implies that hypabyssal magma is beneficial to the gold mineralization in the Dashui area.This is why the large-scale gold deposit was defined in the vicinity of Ge'erkuohe and Zhongqu bodies,but only ore spot was found nearby Zhonggezhala body.