Abstract: Graphite（GRP）powder,silicon（Si）powder,nano-copper（Cu）powder,nano-tungsten（W）powder,and nano-nickel（Ni）powder were selected as the additives in this study.Meanwhile,the additives were added in stearic acid（SA）,paraffin wax（P）,and a P-SA mixture in the proportions of 5%,15%,30%,and 50% respectively,to prepare 63 combinations of composite phase transition materials. The variation of thermal conductivity of the 63 sorts of composite phase transition materials were studied experimentally. The aim of this study was to understand the impact of the five additives on the thermal conductivity of the phase transition materials. The results show that each of the additives can facilitate in the thermal conductivity of the phase transition materials.Among the additives tested,graphite powder displayed the best heat conductance and lowest cost. The addition of nano-tungsten powder to the phase transition materials resulted in poor fusibility and the lowest increase in thermal conductivity. It is not a suitable additive to increase the heat conductance of the tested phase transition materials.