Using a combination of the Monte Carlo models of fast electrons, of molecular ions （N＋） and of atomic species （N^＋, Nf）, the influence of the discharge pressure （P） and voltage （Vc） on the energy distributions of fast atomic species （N^＋, Nf） produced by e^--N2s and N2^＋- N2s dissociation reactions at the cathode in a nitrogen dc glow discharge was investigated. Both the angular distributions and the density distributions along the radius of the species （N^＋, Nf） produced by the two dissociations at the cathode were calculated. The results show that： （1） there is an optimum discharge condition for P and Vc in order to obtain the species （N^＋, Nf） at the cathode with high a density and energy, （2） when the voltage is above 800 V, the species （N^＋, Nf） bombarding the cathode are mainly produced by the N^＋-N2s dissociation, whereas when the voltage is below 300 V, they are mainly produced by the e-N2s dissociation, and （3） at high Voltages the incident angles of a considerable number of Nf into the cathode are quite small. The density of the species （N^＋ Nf） at the cathode increases with the voltage, and when the pressure goes up to about 133 Pa, it decreases with the increasing pressure.
