Highly conductive particles have been used to improve the inherent thermal conductivity of phase change materials (PCMs). To investigate the heat transfer process of PCMs enhanced by nano-particles, the melting process of 15 kinds of nano-particles PCMs (NPCMs) was observed in test tubes with different nano-particles and particle concentrations. The NPCMs were prepared by dispersing nano-coconut shell charcoal with mass fraction ranged from 0.02 wt % to 18.5 wt.% and nano-graphite with mass fraction from 0.02 wt.% to 1.0 wt.% in paraffin-based PCM with a nominal melting temperature range of 26-28 °C. Type T thermocouples were used to monitor the temperature variation of each material under different boundary temperatures in a climate chamber. Thermovision tests were conducted to illustrate the temperature distribution. It was found that Nano-particles was able to enhance the heat transfer of PCMs. The addition of nanoparticles within 0.1 wt.% didn’t affect the phase change characteristics of paraffin.Dispersant was able to enhance the heat transfer of NPCMs. However, when the concentration increased to 18.5 wt.%, more particles were observed at the bottom of the test tubes, causing heat transfer dead zones.