In this paper, the thermal conductivity, dielectric properties and dynamic mechanical properties were studied for Graphene Decorated with Graphene Quantum Dots (GDGQD)-epoxy nanocomposites. A maximum thermal conductivity enhancement of 19% registered for 0.75 wt% GDGQD sample where a low acoustic impedance mismatch between the interface of GDGQD fillers and the epoxy matrix occur and a dielectric constant increase of 6% due to the better charge accumulation at the conductive filler/ insulating polymer interface of the composite. Further DMA is performed using the cantilever mode. The loss modulus peak obtained for 0.75 wt% GDGQD-epoxy sample given a maximum value due to the interface interaction and the corresponding storage modulus shown a maximum increment of 21%, due to the molecular dynamics and cross-linking density of the epoxy matrix with GDGQD. The thermal stability of the samples evaluated using Thermal Gravimetric Analysis (TGA) shown an improvement in glass transition temperature (Tg) of nanocomposite for 0.75 wt% GDGQD by 11 °C where a greater dispersion of the fillers and efficient functional groups interaction are responsible factors. © 2019 IOP Publishing Ltd.