Graphite oxide (GO) was functionalized with different amine groups through the amidation reaction, and their dispersion and interface in epoxy (EP) were investigated. Two types of amine-functionalized graphite oxide were prepared by grafting bifunctional molecule 4,4-diaminodicyclohexylmethane (DDCM) and monofunctional molecule N-Aminoethylpiperazine (AEP), and their epoxy composites were prepared respectively. Fourier transform infrared spectra (FTIR), X-ray diffraction analyses (XRD), and Thermogravimetric analysis (TGA) confirmed the realization of chemical functionalization of GO. The covalent functionalization of graphite oxide with DDCM was favorable to its homogeneous dispersion in epoxy matrix and formed strong interfacial adhesion due to the chemical bonding between GO and the polymeric matrix, while the grafting of AEP on GO failed to do this. Experimental results showed that with the incorporation of only 0.1wt % DDCM-functionalized graphene oxide (DDCM-GO), the mechanical properties and the dispersibility of fillers in the nanocomposites were improved significantly, when compared to the incorporation of AEP-functionalized graphite oxide (AEP-GO). However, the addition of 0.1wt % AEP-GO improved the glass transition temperature (Tg) of nanocomposites by 10°C, compared to neat epoxy. Little improvement of Tg was observed in the epoxy nanocomposites with the incorporation of DDCM-GO. The grafting degree of the amine molecules was also studied.