The paper presents latest results of constricted glow discharge simulations. Detailed self-consistent plasma model includes a large set of plasma chemical reactions, considering inhomogeneous gas heating and accurate solution of radiation transport equation. Results of the computer simulations were compared with an experimental data of positive column constriction in neon and argon. Experimental plasma diagnostics was performed using classic methods of emission and absorption spectroscopy and a line ratios method. Comparison of the obtained results allows to reveal the influence of resonance radiation trapping on the plasma parameters of a constricted discharge.