Chiral ionic liquids, [C(2)mim][LLA], [C(4)mim][LLA] and [C(6)mim][LLA] were firstly applied as both ligand and reaction media for atom transfer radical polymerization using activators generated by electron transfer (AGET ATRP) of acrylonitrile (AN) with ascorbic acid (VC) as reducing agent in the presence of air. A small but clear increase of polyacrylonitrile (PAN) isotacticity was observed for AGET ATRP of AN in [C(6)mim][LLA] than in [C(6)mim][BF(4)]. PAN isotacticity markedly increased with the content of [C(6)mim][LLA]. Compared with in [C2mim][LLA] and [C(4)mim][LLA], the rate of AGET ATRP of AN in [C(6)mim][LLA] was fastest and the polymerization was best controlled. Well-defined PAN with molecular weight at 76,590, relatively narrower distribution at 1.27 and higher isotacticity at 0.37 was successfully prepared in [C(6)mim][LLA]. (C) 2011 Elsevier B.V. All rights reserved.