Abstract: Thermogravimetric analysis coupled to Fourier transform infrared spectroscopy, TGA-FTIR, has been used real time to probe the degradation of polyamide 6 in highly pure N2 with constant rate-controlled heating(10 ℃/min). The results showed that the thermal degradation of polyamide 6 occurs in the range of 320-490 ℃. The amount of residue is 2% at 550 ℃. The evoloved gases, mainly H2O, CO2, aliphatic hydrocarbons and oligomer were determined. The presence of aliphatic hydrocarbons and oligomer indicates that under these conditions alkylamide bond (CH2—NH—CO) scission might occur either by homolytic cleavage or by cis-elimination in the case of polyamide 6.