The strong ability of polyhedral oligomeric silsesquioxane (POSS) to aggregate in nonsolvents makes it interesting to study the self-assembly behaviors of polymer-POSS hybrids. Telechelic poly(styrene-ran-sodium styrenesulfonate) with POSS as the end groups was prepared via end-capping of anionic living polystyrene chains with POSS followed by a mild sulfonation. The morphology and association properties of this new amphiphilic hybrid in an aqueous solution were investigated by dynamic and static light scattering, transmission electron microscopy and atomic force microscopy. The studies reveal that the strong aggregation propensity of POSS leads to a low critical micelle concentration and induces the aggregation of micelles. Hollow supermicellar structures can be observed at a low concentration of 1 mg/mL.