Copolymers with a different degree of distribution of styrene and isoprene blocks are prepared by anionic polymerization. The products are characterized by means of 1H‐NMR spectroscopy, GPC, viscometry, and light scattering. The results show that the copolymers are homogeneous in molecular weight and chain composition. In the investigated selective solvents, cyclohexane and base lubricating oil, and equilibrium exists between micelle aggregates and individual polymer coils. The influence of the copolymer structure on the micellization is more pronounced in cyclohexane.