The investigations of plasma parameters and active particles kinetics in Cl-2 and HCl direct current glow discharges (p=40-300 Pa, j(d) = 8.5 X 10(-3) A/cm(2)) were carried out. The investigation combined plasma diagnostics by Langmuir probes, absorption spectroscopy and self-consistent 0-dimensional plasma modeling based on the solution of Boltzmann kinetic equation. It was found that the model provides an outstanding agreement with experiment on the reduced electric field strength (E/N), Cl atom density and the total flux of positive ions and thus, gives an adequate description of basic kinetic effects determining the steady-state plasma parameters and composition. Under the same operating conditions, Cl-2 plasma provides higher E/N, mean electron energy, dissociation degree and electronegativity that can be explained by the peculiarities of formation-decay kinetics analyzed in both systems. (c) 2007 Elsevier B.V. All rights reserved.