A novel amphiphilic copolymer poly（ethylene glycol）-block-poly（N,N-dimethylamino-2-ethylmethacrylate）-block- poly[6-（4-methoxy-azobenzene-4＇-oxy） hexyl methacrylate] （PEG-b-PDMAEMA-b-PMMAzo） was prepared by ATRP polymerization. The self-assembly and responsive behaviors were investigated by SEM, TEM, LLS and UV-Vis spectra. The results indicated that the copolymers can self-assemble into spherical structures in aqueous media. The aggregate size can be tuned by pH and temperature. The trans-cis isomerization behavior of the formed aggregates was also examined. Upon irradiation with a linear polarized light, the elongation degree of the aggregates was increased with the irradiation time.
