The kinetic reactions in N 2 -χCH 4 (C 2 H 2 ) gas discharges with χ less than 1% have been studied by emission spectroscopy in the afterglow of D.C. discharges and by mass spectroscopy from radiolysis ionization using α particles. The pressure range is from several Torr to 100 Torr.At the end of N 2 D.C. discharges at room temperature, for a residence time of about 10 - 2 s, the dominant active species are the N atoms with density of 10 1 4 -10 1 5 cm - 3 for N 2 density of about 10 1 7 cm - 3 (3 Torr), the N 2 (X, V) vibrational molecules with for example [N 2 (X, V = 10)] 10 1 4 cm - 3 and the electronic metastable molecules N 2 (A 3 + u ) with a density of 10 1 2 cm - 3 . In such conditions, the following kinetic reactions have been studied: N 2 (A) + N 2 (A) → N 2 (C, B, V ) + N 2 (X), N 2 (A) + N 2 (X, V > 5) → N 2 (X) + N 2 (B, V ) in pure N 2 post-discharges and N 2 (A) + CH 4 → products, C + N + M 2 → CN(B, V ) + M 2 , N 2 (X, V > 4) + CN → N 2 (X) + CN(B, A, V ), in N 2 -1% 0 CH 4 post-discharges.The clustering reactions of N 2 -(1-5%)CH 4 (C 2 H 2 ) gas mixtures after radiolysis ionization have been studied for the H 2 CN + nN 2 ions and the equilibrium constants have been determined in the temperature rangeT = 140-300 K.