Decomposition of acetylene to carbon black in dc arc plasma argon jet has been investigated. The power of a plasma generator ranged from 5 to 18 kW. It was found that at mean mass reaction temperature 1270 K the degree of decomposition of acetylene was 96 mol % and product obtained showed a structure suitable for using in a rubber chemistry. The crude carbon black contains small amounts of by-product extractable in organic solvents, as derivates acetylene and polyethylene - like polymers. At temperatures exceeding 3000 K the presence the fullerene-like matters was shown.