Amylose-block-polystyrenes with various block copolymer compositions were investigated in water and in THF solution. Fluorescence correlation spectroscopy, dynamic light, scattering (DLS), and asymmetric flow field-flow fractionation with multiangle light scattering detection indicate the presence of unimers, oligomers, and large micellar species in THF. Up to four different species: were detectable by DLS with hydrodynamic radii ranging from a few nanometers to > 10 mum, indicating that the system is not in a thermodynamic equilibrium state. Collapsed aggregrates were monitored on a Silicon surface by scanning force microscopy and transmission electron microscopy. In water. crew-cut micelles were obtained from the same block copolymers by a single solvent approach, using elevated temperature and pressure. These crew-cut aggregates are much more uniform than the respective star aggregates in THF, and their radii scale with R-h proportional to N-core(1/4), R-h proportional to N-corona(1/6) in solution and with R proportional to N-core(1/4), R proportional to N-corona(1/2) on a silicon surface.