The objective of this paper is to review the recent technologies of thermal energy storage (TES) using phase change materials (PCM) for various applications, particularly concentrated solar thermal power (CSP) generation systems. Five issues of the technology will be discussed based on a survey to the state-of-the-art development and understandings. The first part is about various phase change materials (PCM) in thermal storage applications and recent development of PCM encapsulation technologies. The second is the current status of research and application of latent heat storage systems in CSP plants. The third is the mathematical modeling and numerical simulations to the phenomenon of latent heat thermal storage. The fourth is about the issues of integration of a PCM-based TES unit into a power generation system and the operation. The last part is a discussion about the cost issues and comparison between sensible and latent heat TES systems. The surveyed information will be very helpful to researchers and engineers in energy storage industry and particularly solar thermal power industry.