Abstract The negative glow plasma of a cylindrical hollow cathode dc discharge (0.05 - 1 Torr Argon, 1-30 mA) is investigated as to the position of the glow edge, the axial dependence of the cathode current density, the axial and radial potential distributions, the density and energy of electrons (from Langmuir probe measurements) as dependent on pressure, discharge current and position, etc. It is found that two groups of electrons exist whose energies are < 0.5 eV ~ 3 eV and the ratio of their denisties being 3 up to 20. A phenomenological explanation is given for the relatively high denisty of the fast group, The results are compared with those of other auhors concerning hollow-cathode and linear discharges.