The process of synthesis of carbon deposits from hydrocarbon vapours in low-current electrical-discharge plasma was investigated in the paper. The carbon deposits were effectively synthesised in discharge of positive polarity generated between a stainless steel needle and a plate made of nickel alloy, for the discharge current ranged from 0.1 mA up to 3 mA. The experiments were carried out at normal pressure in cyclohexane vapours with argon as carrier gas. The process of synthesis of carbon deposits was investigated using optical emission spectroscopy.