Abstract The copolymer of acrylamide and octylphenylpoly(oxyethylene) acrylate macromonomer (AM-C8PhEO7Ac) was synthesized and characterized by IR and NMR spectroscopy. The molecular weight of the copolymer was determined to be 1.21105 by static light scattering. The weight contents of AM and macromonomer were determined to be 67.8 and 32.2%, respectively, by elemental analysis. The micellar behavior of the copolymer in aqueous solution was studied by UV spectroscopy and atomic force microscopy (AFM). The molecules of AM-C8PhEO7Ac copolymer form monomolecular micelles in the concentration range 41063 105g/ml and polymolecular micelles at concentrations above 3105g/ml according to the UV analysis. The AFM images indicate that the monomolecular micelles are globular with diameters of 70nm and have a narrow size distribution. The polymolecular micelles can be globular or cylindrical depending on the concentration, and have a wide size distribution.