The polypropylene-graft-cardanol (CAPP) was prepared by reactive extrusion with polypropylene (PP) and natural renewable cardanol which could improve the inherent defects of PP such as chemical inertness and hydrophobicity. Moreover, the cardanol grafted onto PP could resolve the degradation of PP during the process of reactive extrusion. In this paper, CAPP was prepared in the presence of three different kinds initiator. The compatibilization and the anti-aging performance of cardanol grafted onto PP were studied. Results showed that the initiator dicumyl peroxide (DCP) exhibited the optimum initiated efficiency. Cardanol grafted onto PP was benificial for the composite of bamboo powder and PP.The initiator of DCP caused the degradation of PP chains during the aging processing. After aged for 24 h, the yield strength decreased from 28 MPa to 15 MPa and the elongation at break reduced by 795 %. The CAPP possessed outstanding anti-aging performance owing to the cross-linking and entanglement of the side chains of cardanol grafted onto PP. The yield strength, tensile strength and the elongation at break of CAPP-DCP changed lightly even when it was in long-term irradiation for 480 h.