Abstract: In order to study the physical properties of RP-3 aviation kerosene and its impurities, three tanks from different oil inlet and outlet units were sampled during the receiving and dispatching operation of an airport oil depot in North China, and the samples of aviation kerosene and its solid impurities were obtained by filtration. Further, the density, viscosity and water content of aviation kerosene sample were measured with a densimeter, a capillary viscometer, a distillation flask and other experimental instruments, and for the solid impurities, electron microscope scanning and energy dispersive spectrum analysis were carried out. The results show that the kinematic viscosity, density and water content of aviation kerosene in the three tanks are 1.651 2-1.868 8 mm²/s, 0.794 9-0.795 6 g/cm³ and 0.007%-0.009% respectively. The solid impurity particles are spherical, rod-shaped, long block-shaped or tetrahedral. The particles are mainly composed of nonmetallic elements such as C, H, O and Si, and metallic elements such as Ca, Al, Mg, Fe, Mn, Co, Ti, K and W. The particle size is ranged of 8-1.5×10⁴ μm, and the impurity particles sized less than 150 μm, 50-100 μm, 30-50 μm and other size range account for about 83%, 15%, 2.3% and 0.1% respectively. The impurity particles more than 150 μm are easy to be separated, while those less than 150 μm are hard to be separated with the conventional methods. Taking the impurity particles sized 20-150 μm for example, the density was measured by pycnometer method, and the density change function model was fitted on this basis, which could provide effective guidance for separation of aviation kerosene solid impurities.