The fracture strain for the composite of poly(L-lactic acid) (PLLA) and double-fullerene end-capped poly(ethylene oxide) (FPEOF) was observed about 100 times of PLLA with a high modulus for room-temperature aged samples. The aggregates of fullerene of FREOF ends give rise to the formation of physical network of poly(ethylene oxide), which forms a pseudo-semi-interpenetrating network with PLLA and renders the astonishing enforcing effect on the PLLA.