The morphologies of films spin coated from star-like poly(styrene-b-ethylene/butylene-b-styrene) triblock copolymer (SEBS)/toluene solution onto a mica substrate were studied by atomic force microscopy (AFM). The results showed that the solution concentration determined the morphology of the aggregates, which displayed from single coil, spheres, network structure and continuous film with the increasing concentration. The size of aggregates could be influenced by the solubility of the solvent. With the increase of the solubility, the solvent could easily penetrate into the macromolecules, which resulted in the height of the aggregates on the surface of the film decreasing. The size of the aggregates could evolve to perfect spheres with heat treatment temperature. A lot of bubbles and pores could be observed at the morphology from the film spin coated immediately after ultrasonic treatment. Comparing the AFM patterns of linear SEBS (L-SEBS) with star-like SEBS (S-SEBS) under the same conditions, it was found that the size of aggregates of L-SEBS was smaller and the morphology was more difficult to change due to the steric hindrance and poor mobility of molecule chains of S-SEBS.