Polytetrahydrofuran macroinimers were synthesized by means of cationic polymerization of tetrahydrofuran, initiated by azo-oxocarbenium salt, followed by termination with methacrylate anion. The macroinimers were characterized by H-1-NMR analysis and GPC measurements. Self polymerization of macroinimers and copolymerization with methyl methacrylate (MMA) yielded crosslinked and soluble branched block copolymers depending on the MMA concentration.