A novel stabilizer containing hindered phenol and hindered amine light stabilizer (HALS) group in one molecule was prepared through the acyl chloride reaction followed by the amidation reaction. Its structure was characterized by electrospray ionization mass spectrometry (ESI-MS) and proton nuclear magnetic resonance (1H-NMR), Fourier transform infrared spectroscopy (FT-IR). The thermogravimetric analysis (TGA) results under nitrogen and air atmosphere indicated that the addition of the novel stabilizer efficiently improved the thermal and thermal-oxidative stability of polyamide 6 (PA6). The thermal-oxidative stabilization effect of the novel stabilizer on PA6 was further evaluated in terms of reduced viscosity, tensile properties, and chemical structure after accelerated thermal aging in an air circulating oven at 150°C. The results indicated that the novel stabilizer could improve the thermal-oxidative stability of PA6 effectively, resulting in the high retention of reduced viscosity and tensile strength, and the low ratio of terminal carboxyl group to amino group. The mechanism of the novel stabilizer on the thermal-oxidative stabilization of PA6 was also discussed. POLYM. ENG. SCI., 54:2197–2206, 2014. © 2013 Society of Plastics Engineers