The flame-retardant properties and impact fracture toughness for the polypropylene (PP) composites filled, respectively, with intumescent flame retardant (IFR) and nanometer calcium carbonate/polyolyaltha olefin were measured in the present paper. It was found that the limited oxygen index increased nonlinearly, whereas the horizontal combustibility rate decreased with increasing the IFR weight fraction (phi(IFR)). The smoke density rank increased with increasing phi(IFR). The values of both the V-notched Izod impact strength and Charpy impact strength of the composites were higher than those of the unfilled PP; they decreased slightly with an increase of phi(IFR) when phi(IFR) was more than 10%. Moreover, the fracture surface of the specimens was observed using a scanning electronic microscope to discuss the mechanisms of the flame retardant and toughening.