Abstract: The porosity and splitting characteristics of asphalt concrete are significantly affected by the properties and contents of each raw material, which directly affect its impermeability and stability. The influence of gradation index, filler content and asphalt content on the porosity and splitting characteristics of asphalt concrete is analyzed systematically to provide a basis for the construction mix proportion design research of asphalt concrete. Based on the control variable method and the same compaction times, the variation laws of porosity and splitting characteristics of standard Marshall specimens under the conditions of 4 grading indexes, 4 filler contents and 4 asphalt contents are systematically analyzed. The results show that the porosity and splitting displacement decrease with the increase of grading index, and decrease by 29.33% and 39.13% respectively. With the increase of filler content, it first decreases and then increases, and the minimum filler content is 12%. With the increase of asphalt content, it first increases and then decreases, and the maximum is when the asphalt content is 6.8%. The splitting strength increases with the increase of gradation index, and increases by 23.98%. It decreases gradually with the increase of filler content and asphalt content, and decreases by 11.59%and 22.32% respectively. Based on the grey dominance analysis, filler content and asphalt content have the greatest influence on the splitting strength of asphalt concrete, followed by porosity. The filler content has the most significant effect on porosity and splitting characteristics, followed by asphalt content and gradation index.