Living polymerization of phenylacetylene (PA) was achieved with new catalyst systems composed of a cationic rhodium complex, [(tfb)Rh(PPh3)(2)]BPh4 (2, tfb = tetrafluorobenzobarrelene) and amines as cocatalysts. Applying i-PrNH2 as a cocatalyst, the PDI of the formed poly(PA) was as small as 1.09. Kinetic plots and multistage polymerization proved the livingness of the present polymerization.