Polyurethane-polymethacrylic acid multi-block copolymers were synthesized from tetraphenylethane based polyurethane iniferter. Number of polymethacrylic acid blocks and molecular weight of block copolymers increased with increasing polymerization time which proves that the formation of block copolymers is through a "living" radical mechanism. The multi-block copolymers obtained were converted into their sodium anionomers. The multi-block copolymers and their anionomers have been characterized by FTIR, FTNMR and DSC analysis.