Poly(2-vinyl pyridine-b-styrene-b-2-vinyl pyridine) BAB type block copolymers were synthesized by anionic living polymerization. The micelle formation of these BAB type triblock copolymers was carried out in toluene and toluene/cyclohexane mixture, and estimated with dynamic light scattering for the polymer solutions. Poly(2-vinyl pyridine) sequences in core part of the polymer micelles of the BAB type block copolymers were crosslinked with 1,4-diiodobutane. Upon crosslinking, no macrogelation was observed and the poly(2-vinyl pyridine) core-polystyrene shell type spherical microgels were synthesized.