We report the micellar behavior of polystyrene/poly(2-vinyl pyridine) heteroarm star copolymers (PS(n)P2VP(n)) in toluene which is a selective solvent of polystyrene. A series of PS(n)P2VP(n) were synthesized by anionic polymerization and their micellar characteristics such as critical micelle concentrations (cmc), aggregation numbers, hydrodynamic dimensions and core-corona sizes were determined by the means of static and dynamic light scattering, viscometry and transmission electron microscopy. All these parameters were studied as a function of the insoluble arm length and the corresponding scaling relations were established. Our system seems to belong to the class of amphiphile micelles characterized by strong dependencies of the aggregation number and the microdomain sizes on the insoluble arm length. This behavior is also characteristic of strongly segregated diblock and triblock copolymer systems.