New monodisperse ethylene-propylene copolymers and a block copolymer, highly syndiotactic polypropylene-b-poly(ethylene-co-propylene), were synthesized with a titanium complex having fluorine-containing phenoxy-imine chelate ligands, an FI Catalyst, using methylalumoxane (MAO) as a cocatalyst. Analysis using transmission electron microscopy (TEM) suggests that the well-defined block copolymer possesses high potential as a compatibilizer.