Thermal management is one of the most critical issues in miniaturized electronic devices with increasing power density. Herein, with the aid of direct atmospheric pressure chemical vapor deposition, a novel type of highly oriented graphitic network is demonstrated, either coated on alumina powder or in the form of thick flake, as thermal conductive fillers in non-curing thermal interfacial materials. The adoption of hybrid size fillers leads to compact packing structures in the silicone base and provides more effective pathways for phonon transport in thermal interfacial materials, which decreases the thermal boundary resistance and improves the thermal conductivity of the silicone-based thermal paste. The thermal performance is even better than some of commercial graphite-based thermal pastes used in the heat dissipation experiment. Compared with the silicone base, an enhancement in thermal conductivity of 3008% is obtained (from 0.13 to 4.04 W/m.K) with thick graphitic coating. Even at elevated temperatures, these thermal pastes maintain good deformability and stable thermal conductivity in the experiment.