Molecular dynamics simulation method with an improved flexible nitrate model was used in this paper to study the structure and properties of molten LiNO3, NaNO3, and KNO3. Both local structure and physical properties including densities, thermal conductivities, viscosities and heat capacities of the salts were simulated comprehensively. Different simulation methods were used and the results were compared with experimental data. The relationship between the structure and properties of the salts were discussed. Besides, a binary mixture of NaNO3 and KNO3 was also simulated to verify the applicability of the force field and simulation method for salt mixtures. The results indicate that the force field and simulation methods adopted in this paper work well in predicting the properties of both single nitrate salts and their mixtures. This paper did a basis job for further investigation into the simulation of nitrate salt mixtures used in thermal energy storage. (C) 2019 Elsevier Ltd. All rights reserved.