“…Liu [18] first considered a general 2 × 2 relaxation system in one spatial dimension, and gave the stability criteria for the shock waves, rarefaction waves and also diffusion waves. Since then, many authors have studied the stability of shock waves and rarefaction waves to the relaxation system in one or several space dimensions; see [3][4][5][6][7][8]16,17,[21][22][23][24][25]27,[31][32][33][34], etc. However, as far as we know, there is no result corresponding to contact discontinuities for the relaxation system (1.1).…”