Stepwise anionic polymerization, catalytic hydrogenation, and atom transfer radical polymerization were performed to synthesize an amphiphilic ABC triblock co-polymer, poly(ethyl-alt-propylene)-block-poly(ethylene oxide)-block-poly(hexyl methacrylate) (PEP-b-PEO-b-PHMA), with hydrophilic PEO as the middle block. The resulting block copolymers have well-defined molecular weights and narrow molecular weight distribution as revealed by H-1 NMR spectroscopy and gel permeation chromatography.