Polyethylene-poly(methylmethacrylate) (PE-PMMA) polymer hybrid was synthesized via RAFT polymerization of MMA with PE chain transfer agent (PE-CTA) for the first time. The structure of PE-CTA produced by sequential functionalization of terminally hydroxylated PE was confirmed by H-1 NMR and FT-IR analyses. The results of GPC after MMA polymerization revealed that the molecular weight (M-w) of the resulting polymers increased compared with the one of the PE-CTA. H-1 NMR analysis of resulting polymers confirmed that the amounts of PMMA segments were in a range of 7.8 and 23 wt%. TEM images indicated the nanometer level microphase-separation morphology between the PE segment and PMMA segment.