Abstract: Two main drawbacks of most phase change materials are the low thermal conductivity and thermal stability. To address the above-mentioned problems, carbon bonded carbon fiber-graphite nanoplatelets (CF-GNP) network was first prepared using a slurry molding method. And molten paraffin was infiltrated into the CF-GNP network to form a CF-GNP/paraffin phase change composites. The effects of CF and GNP contents on the structure of the CF-GNP network and thermal properties of the CF-GNP/paraffin composites were systematically studied. The results show that the melting-solidifying rates are greatly accelerated for the CF-GNP/paraffin composites comparing to pure paraffin. The less the CF loading amount is, the more the effect of GNP on heat enhancement is. For the CF-GNP/paraffin composites with 50wt% CF and 10wt% GNP in the CF-GNP network, the melting time is shortened by 39.9% comparing with the CF/paraffin composite with only 50wt% CF in network. The decrements are 24.5% and 9.4% for CF/paraffin composite with CF loading of 70wt% and 85wt%, respectively. The tests of 40 thermal cycles indicate that the CF-GNP/paraffin composites prepared in this study show good thermal stability.