Hybrid materials LGC were prepared with the L-aspartic acid connected graphene oxide and the acidified MWCNT (WMCNT-COOH) as raw materials. Then nanocomposites of LGC/HDPE-g-MAH with different amount of LGC were prepared by melt blending method with maleic anhydride grafted high density polyethylene (HDPE-g-MAH) as raw material and LGC as nano-fillers. The LGC hybrids and LGC/HDPE-g-MAH nanocomposites were characterized by using Fourier transform infrared spectroscopy (FTIR), Raman spectrum (Raman), X-ray diffraction (XRD), Scanning electron microscope (SEM), Differential scanning calorimetric analysis (DSC), Thermogravimetric analysis (TGA), Dynamic mechanical analysis (DMA) and mechanical properties characterizations. Results show that L-aspartic linked effectively GO and WMCNT-COOH, while the LGC formed via an amide bond. Functional groups (amino or carboxyl group, etc.) in LGC may interact with the carboxyl groups of polymer matrix, which improved the interface between the matrix and the filler; the changes of dissipation factor verified that strong interactions exist between LGC and HDPE-g-MAH matrix chains; therewith the crystallization temperature, melting temperature and thermal stability of nanocomposites were enhanced; while with the increasing amount of LGC, the tensile strength and impact strength of the nanocomposites increased first and then decreased, by addition of 0.5%and 0.75%(mass fraction) LGC, the impact strength and tensile strength of the nanocomposites were enhanced by 95.9% and 62.4% respectively in comparison , with the blank HDPE-g-MAH.