Giant vesicles containing 2-(dimethylamino)ethyl methacrylate (DMAEMA) and its quaternary ammonium salt in the hydrophobic cores or hydrophilic shells composed of poly(methacrylic acid)-block-poly(methyl methacrylate-random-methacrylic acid), PMAA-b-P(MMA-r-MAA), were prepared using the photo nitroxide-mediated controlled/living radical polymerization (photo NMP). The photo NMP of DMAEMA and its quaternary ammonium salt with trifluoroacetic acid was confirmed to have the living nature based on the gel permeation chromatography analysis. The photo NMP was performed for the block copolymerization of methyl methacrylate (MMA), methacrylic acid (MAA), and DMAEMA or its quaternary salt using PMAA end-capped with 4-methoxy-2,2,6,6-tetramethylpiperidine-1-oxyl in an aqueous methanol solution. The photo NMP-induced self-assembly of the amphiphilic diblock copolymer produced spherical vesicles. The vesicles with DMAEMA in the hydrophobic phases of the P(MMA-r-MAA) block were unstable and had many holes in the surface, while those with the quaternized DMAEMA were stable and had much smaller size. An increase in the quaternized DMAEMA in the hydrophobic block transformed the vesicles into unstable and larger spherical vesicles, and finally into stratiform sheet. On the other hand, the incorporation of the quaternized DMAEMA into the hydrophilic shells of the PMAA block reduced the size of the spherical vesicles and retained the vesicle structure against an increase in the hydrophilicity of the hydrophobic P(MMA-r-MAA) block.