A poly(butyl methacrylate)-block-poly(2-cinnamoyloxyethyl methacrylate)-block-poly(tertbutyl acrylate) or PBMA-b-PCEMA-b-PtBA triblock copolymer was synthesized and characterized. The triblock formed spherical aggregates with PBMA and PtBA coronas and PCEMA cores in 2-propanol containing 1 vol % THF. Triblock nanospheres were obtained after photo-cross-linking the PCEMA cores. Nanospheres with amphiphilic coronal chains were obtained after hydrolyzing the tert-butyl groups selectively.