Abstract: Three samples, C364 carbon black, C364 carbon black pigment after a two step ozone oxidation, and MA100 from Mitsubishi Corporation, were characterized by XPS, IR, SEM, PY-GC/MS spectroscopy and elemental analysis. The processing parameters, mechanical properties, aging resistance and micro-morphology of the oxidized C364 carbon black pigment and its composites with polyethylene, polyvinyl chloride and poly(acrylonitrile-butadiene-styrene) resins were characterized by a HAAKE torque rheometer, scanning electron microscopy and an aging test chamber. Results show that oxidized C364 carbon black pigment contains more hydroxyl, carbonyl, carboxyl and other functional groups than the original C364 sample. The mechanical properties of the composites with oxidized C364 carbon black pigment were almost the same as those of MA100-based ones. Oxidation of the C364 carbon black pigment significantly increased the photo aging lifetime of the polyethylene-based composite 10 times.