To study the dispersity of different amine-graphene oxide (amine-GO) in polymer matrix and the interfacial interactions between functionalized graphene oxide and matrix, two kinds of modifiers-organoamine- and aminosilane-coupling agents-were used to functionalize graphene nanosheets to obtain functionalized graphene oxide/waterborne polyurethane nanocomposites by in situ polymerization. The chemical structure, morphology, and interlayer space of amine-GO nanoplatelets were confirmed by FT-IR, Raman, TGA, XPS, TEM, AFM, and XRD. The dispersity behaviors between different amine-GOs and polymers were evaluated by FESEM. The thermal, mechanical, and hydrophobic properties of the nanocomposites were investigated by TGA, tensile testing machine, and water contact angle test, respectively. It was found that the tensile strength of nanocomposites was increased from 10.13 to 27.79 and 28.96 Mpa after the addition of amine-GO functionalized by APTMS and APTES, respectively. The better thermal stability and hydrophobicity of nanocomposites were also achieved by the addition of amine-GO, especially those modified by aminosilane-coupling agents. This study paves a new route for designing and developing chemically converted graphene oxide nanosheets/polymer nanocomposite materials by altering suitable amine-modifier to functionalize graphene oxide nanosheets and then optimizing the interphases between graphene oxide nanosheets and polymer matrices.