Degradation induced by thermal (50-110 °C) and radio-oxidation of low T g epoxy-amine networks has been studied. It has been found that oxidation leads mainly to amide groups formation at the vicinity of tertiary amines whatever ageing conditions (thermal or radio-oxidation at 200 Gy h -1 ). In addition, some species as acids, peracids or formates have been revealed indicating a chain scission process. Physical modifications as T g decrease and soluble fraction increase due to chain scission process, have been correlated with chemical modifications.