Gra,nitoids in southern Da Hinggan Mountains might be mainly divided into Hercynian and Yanshanian intrusions. The Hercynian granitoids related to plate subduction belong to calc-alkaline orogenic granitoid series formed in a compressional environment, whereas the Yanshanian granitoids related to epicon- tinental taphrogeny are of subalkaline-alkaline anorogenic granitoid series produced as a result of mantle uprising .in an。extensional environment. With the elapse of time the Yanshaaian granitoi.ds gradually increased in alkalinity and get intensified in extension. The two granitoid series are different conside- rably not only in tectonic environments, geomorphology and shapes of intrusions, but also in rock assemblages, emplacement patterns, rock-forming minerals, petrochem}istry, trace elements, initial ratio of Sr isotopes and δ18O values as well as in mineralization governed by them.