［Objective］As a new type of soil amendment，the impact of water-storage clay on the hydraulic properties of soil on the Loess Plateau is still unknown. The aim of the study was to investigate the effects of different particle sizes and application rates of water-storage clay on soil hydraulic properties.［Methods］Silty loam from the topsoil of Xishan Mountain in Taiyuan City，Shanxi Province，was selected as the test soil for indoor physical experiment. Two particle sizes of water-storage clay（M：2-5 mm，L：5-10 mm）and four application rates of water-storage clay（0，5%，10%，20%）were set. By measuring the soil water characteristic curve and saturated water conductivity，the changes of soil hydraulic parameters under different particle sizes and application rates were analyzed.［Results］1）Compared to the control（CK），water-storage clay enhanced soil infiltration and retention capacity. The improvement in soil water retention was more pronounced with increasing application rates and particle sizes. 2）The particle size and application rate had different degrees of influence on the parameters of the Van Genuchten model. 3）With changes in the application rate and particle size of water-storage clay，the field capacity increased from 27.99% to 31.49%，the wilting coefficient increased from 5.85% to 12.66%，the air capacity increased from 19.15% to 24.68%，and saturated water conductivity increased by 96.56% to 1 150.76%. 4）The order of increase in specific water capacity was M20>L20>M10>L10>L5> M5>CK （M and L represent particle sizes of 2.5 and 5-10 mm for the water-storage clay；5，10 and 20 represent the mass application rates of 5%，10% and 20% for the water-storage clay；CK represents the control without the addition of water-storage clay）. The pore size distribution across different treatments showed the same pattern of storage pores>residual pores>transfer pores>crack pores.［Conclusion］The findings can provide theoretical support for the improvement of soil and water conservation on the Loess Plateau by adding water-storage clay.