Highly armed (AB)(n)-type star copolymers (arm numbers n = 41, polyisoprene blocks = 16 wt%) were prepared by crosslinking poly( styrene-b-isoprene) diblock anions with divinylbenzene. Structural ordering of star copolymers was investigated through the small-angle X-ray scattering measurements in benzene solution. The star copolymers formed the lattice with a body-centered cubic structure near the overlap concentration.