In this paper, natural rubber (NR)/graphene (GE) composites were prepared using an ultrasonically-assisted latex mixing and in situ reduction (ULMR) process. A thermal constants analyzer measured the thermal conductivity of the NR/GE composites using the transient plane source (TPS) method. Results showed that GE had a good thermal conductivity, and can be used as a thermal conductivity enhancer in polymers....