Organic phase change materials have attracted tremendous attention and been employed into various occasions in merit of the isothermal process. For advanced applications of organic composite phase change materials (CPCMs)

the main concern is the low thermal conductivity limiting the thermal conduction speed. In this regard

numerous kinds of functional nanoparticles have been introduced into to engineer high thermal conductivity of CPCMs. In this review

to provide guidelines to fabricate high-performance CPCMs

the heat conduction mechanism as well as the effect of thermal conductivity on the applications of CPCMs was discussed. Based on the mechanisms

the strategies relying on nanoparticles such as graphene

carbon nanotube

boron nitride

etc

. to reinforce the thermal conductivity of CPCMs were reviewed. Furthermore

the perspective of future challenges and directions on the development of CPCMs were presented. The review is intended to inspire the better fabrications and applications of highly thermally conductive CPCMs.