An anisotropic thermal conductivity phase change composite was successfully prepared. The carbon nanotube array(CNT array) is infiltrated byRT100. The as-prepared RT100/CNT array composite is determined by SEM and XRD and the results show that the RT100 is mostly encapsulated in the pores of CNT array. The DSC measurements indicate that the melting temperature and latent heat of the composite are 87.5 degrees C and 195.5 J g(-1), respectively. The as-prepared composite shows 51-fold thermal conductivity enhancement as compared to RT100 and anisotropic thermal conductivity. The RT100/CNT array with anisotropic thermal conductivity could be used in specific application, such as the direct solar thermal storage systems. Further, the as-prepared PCM composite shows great thermal photo-driven performance when placed under the solar simulator. Hence, the RT100/CNT array has great potential in solar thermal utilization.