Vesicles of a noncovalent dumbbell-shaped amphiphilic triblock copolymer were formed by self-assembly of host-guest inclusion between β-cyclodextrin containing poly(ethylene oxide) (β-CD-PEO) and adamantyl group containing polystyrene (AD-PS-AD) in solution. Addition of water into the copolymer resulted in the formation of new bowl-shaped and vesicle morphologies by adjusting not only ratio of solvents (THF dioxane or DMF) but also the length of the PS middle block in the guest polymer, which was ascribed to the large compound micelles (LCMs). The continuous phase of PS was composed of an assembly of reversed micelles (PEO core and PS corona) with hydrophilic PEO chains surrounding the structure at the polymer/aqueous solution interface in the larger compound micelles.