This paper presents the successful results obtained from redox initiated polymeriza-tion of acrylonitrile in concentrated aqueous solution of sodium thiocyanate．The redox systems studied were tertiary-butyl hydroperoxide (TBH) with triethanolamine (TEA)，di-ethanolamine (DEA)，mono-ethanolamine (MEA) and N，N’-dimethylaniline (DMA) res-pectively．In the case of TBH-TEA with mole ratio 1：1 in combination，conversion in one hour was around 90％ and the average molecular weight of the polymer obtained was around 85，000． It was found that the polymerization rate and conversion percentage for different redox systems were in the following order：TBH．TEA>TBH-DEA>TBH-MEA，and the order of average molecular weight of polymer obtained was just in the reverse．Both the rate of polymerization and the maximum conversion percentage increased with increase either in TBH or amine concentration． In the case of TBH-DMA，the maximum conversion obtained was around 60％，the rate of polymerization also jncreased with increase in the mole ratio of DMA／TBH，but the ultimate conver-sion percentage decreased in comparison with the case of the benzoyl peroxide (BPO)-DMA system for st3rrene as monomer．A possible reaction mechanism of TBH-amine system was then suggested．