Abstract: Understanding the hydraulic properties of soil is key to ecological hydrological simulation, agricultural water management and environmental monitoring. However, soils are extremely complex due to its spatial variability, which makes the determination of its physical properties, specially hydraulic properties very difficult. Often, test results are random and demand substantial manpower and material resources to acquire, yet soil property is difficult to describe accurately. In this report, based on a comprehensive analysis of more than 30 research methods for quantifying soil hydraulic properties, we summarized the advantages and disadvantages of using fractal theory to study soil physical properties, and analyzed the relationship between fractal theory and soil hydraulic properties. We aimed to explore the prospects and advantages of using soil fractal structures in hydraulic property determination. The results show that (1) it is feasible to use fractal analysis to study soil structure quantitatively; (2) fractal structural analysis can reveal hydraulic properties and provide a scientific basis for quick and accurate characterization of water distribution in soils at different scales; and (3) use of known soil hydraulic properties can inversely reveal soil structure effectively.

Key words: soil structure, soil particle size, fractal dimension, soil hydraulic properties