Vinylbenzyl-terminated polyisoprene (PI) macromonomers were synthesized by the coupling reaction of the corresponding living anions with p-chloromethylstyrene. PI stars were prepared by the free-radical crosslinking of PI macromonomers with divinylbenzene (DVB) in n-heptane. No macrogelation was observed during polymerization. The radical copolymerization of PI macromonomer with DVB led to microgelation in micelles formed by PI macromonomers in the selective solvent (organized polymerization). The arm number of star polymers depended strongly on the concentration ratio of DVB to macromonomer ends.