The Dazhuangke granitoid complex bodies in Beijing generally contain micro-to fine-grained inclusions. There are more inclusions in quartz diorite and quartzmonzonite, a small amount of inolusions in monzonitic granite and scanty inclusionsin diorite and leucogranite. In those bodies with more inclusions, the inclusionsare likely distributed in the central part of an intrusion. Calculation results showthat the larger the minimum radius of drifted inclusion and the lower the valueof the parameter F is,the more inclusions the intrusive body contains.More inclusionsare detained where the magma ascends more rapidly and the inclusions settlerather slowly. The quaility of inclusions in various intrusive bodies depends on thediffusion coefficient and mixing degree of the inclusions in the host magma, theinclusions carrying capacity of the magma and the mixing in volume of the basicmagma.