In this study, a novel type of amphiphilic block copolymers poly(lactic acid)-block-poly(ascorbyl acrylate) (PLA-block-PAAA) with biodegradable poly(lactic acid) as hydrophobic block and poly(ascorbyl acrylate) (PAAA) as hydrophilic block was successfully developed by a combination of ring-opening polymerization and atom transfer radical polymerization, followed by hydrogenation under normal pressure. The chemical structures of the desired copolymers were characterized by (1)H NMR and gel permeation chromatography. The thermal physical properties and crystallinity were investigated by thermogravimetric analysis, differential scanning calorimetry, and wide angle X-ray diffraction, respectively. Their self-assembly behavior was monitored by fluorescence-probe technique and turbidity change using UV-vis spectrometer, and the morphology and size of the nanocarriers via self-assembly were detected by cryo-transmission electron microscopy and dynamic light scattering. These polymeric micelles with PAAA shell extending into the aqueous solution have potential abilities to act as promising nanovehicles for targeting drug delivery. (C) 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 49: 3988-3996, 2011