The aim of this study was to explore the influence of gravel on infiltration characteristics of the colluvial deposit. The cutting ring method was used to study the changes of infiltration characteristics of the colluvial deposit that mixed with different content and size of gravel. The results were as follows: (1) The steady infiltration time of the colluvial deposit was between 9 and 10 min when the content of gravel was 0%

10%

20%

and 30%

but it was between 19 and 20 min when the content of gravel was 40% and 50%. (2) The initial infiltration rate

steady infiltration rate

average infiltration rate

and accumulative infiltration volume of the colluvial deposit were enhanced with the increasing gravel content. The infiltration parameters changed little at 10%

20%

and 30% gravel content when the colluvial deposit was mixed with gravels of of 2-3 mm

3-5 mm

and 5-10 mm size. The values of infiltration parameters decreased with increasing size of gravels when the gravel content was 40%; when the gravel content was 50%

the values of infiltration parameters of the colluvial deposit mixed with 2-3 mm gravel were the least. (3) A further comparison showed that the Kostiakov model was more suitable for simulating the infiltration process of the colluvial deposit.