A novel catalyst system based on La(0)/hexamethylenetetramine (HMTA) complexes is used for single electron transfer-living radical polymerization (SET-LRP) of acrylonitrile (AN) in the presence of ascorbic acid (VC) with carbon tetrachloride (CCl4) as a initiator and N,N-dimethylformamide (DMF) as a solvent. Compared with SET-LRP of AN in the absence of VC, monomer conversion is markedly increased. SET-LRP of AN in the presence of VC is also conducted in the presence of air. The kinetic studies show that the polymerizations both in the absence of oxygen and in the presence of air proceed in a well-controlled manner. With the respect to the polymerization in the absence of oxygen, the polymerization in the presence of air provides slower reaction rate and broader polydispersity. Effects of amount of VC, La, CCl4, and are investigated in detail. (c) 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2013, 51, 4088-4094