【Objective】Soil structure is the physical framework for various processes in soils and is of great importance for quantitative studies of soil physical, chemical and biochemical processes. Existing methods for quantifying soil structure are overly dependent on laboratory techniques, resulting in them being limited by factors such as sample size, resolution and cost. 【Method】To overcome these limitations, this study utilizes digital imaging techniques to quantify ped shapes using high-resolution soil profile images. 【Result】The results show that typical structural classifications and subjective descriptions can be transformed into quantitative morphometric (circularity, roundness, major-axis ellipse angle,aspect ratio, solidtity, width-to-height ratio) data.Also, the average circularity, roundness, and width-to-height ratio of ped in the topsoil layer in the nine soil profiles (0.79, 0.74, and 1.05) were higher than those in the heart soil layer and the parent soil layer (0.64, 0.68, and 0.94), and their average aspect ratio and major-axis ellipse angle (1.35 and 42.73) were lower than those of the heart soil and parent material layers (1.79 and 49.33).【Conclusion】Therefore, the use of digital imaging techniques can accurately quantify and visually characterize the morphology of ped shape, and the technology elucidates the law that the shape of ped gradually transforms from blocky structure to granular structure in the process of soil formation.