A series of hyperbranched polymers were synthesized in high yield by self-condensing vinyl polymerization (SCVP) of 2-[(2-bromobutyryl)oxy]ethyl methacrylate (BBEM) in the presence of an ATRP initiator: THABP (a tetrafunctional initiator)/CuBr/bpy. The structure and properties of the polymers obtained were characterized by NMR and SEC/RALLS/DV/RI. The effect of the tetrafunctional initiator on degree of branching (DB), molecular weight and molecular weight distribution of polymers was studied.