Abstract: Nitrates are widely used as heat storage mediums in the concentrating solar power system due to their low costs and wide operating temperature ranges. It can significantly improve the heat transfer and storage performance of the nitrates incorporated with nano-fillers, by which the power generation efficiency of the concentrating solar power system can further be improved. In this review, the components and preparation methods of nitrate composite materials were introduced. Then, the effects of the doping concentration and size of the nano-fillers on the heat transfer and storage properties of nitrate composites were analyzed. The enhancement mechanisms of the thermal performance were also summarized. Finally, the future research directions of the nitrate composite systems were outlined.