The synthesis of amphiphilic linear-hyperbranched graft-copolymers in a grafting-from approach is reported. The linear polyethylene with terminated hydroxyls, prepared by copolymerization of ethylene and 10-undecen-1-ol, was used as macroinitiator for ring-opening multibranching polymerization of glycidol by a typical slow monomer addition approach. Successful attachment of the hyperbranched grafts to the linear polyethylene backbone was confirmed by H-1/C-13 NMR, GPC, and TGA. The degree of polymerization and M-w/M-n of hyperbranched grafts were efficiently controlled by temperature, deprotonation ratio as well as the molar ratio of glycidol/hydroxyl (N-glycidol/N-OH). The complicated microstructures caused by unsymmetric glycidol structure were analyzed by DEPT and 2D HSQC spectra, the degree of branching of 0.63-0.66 were calculated, indicating the extent of branch is close to theoretical values. The thermal analysis of linearhyperbranched copolymers via TGA and DSC is also presented. To our knowledge, this is the first report of a linearhyperbranched graft-copolymer with a crystalline and nonpolar linear-polyethylene segment. (C) 2014 Wiley Periodicals, Inc.