Abstract:Soil water availability is one of the key factors on the productivity of lithosols. The study results showed that the soil water availability has a closely relationship with the ratio of soil(fine earth <2 mm) and gravel (grain more than 2 mm). The abilities of soil vaporization, water retention, water conductivity and water supply are associated with the ratio of soil and gravel. Among the studied three types of soils with different ratio of soil and gravel, the soil with the lowest ratio of soil and gravel had highest water retention ability, while the soil with higher ratio of soil and gravel had lowest one. There was a positive relationship between soil water diffusivity and gravel capacity, but a negative relationship between soil vaporization and gravel capacity. A mezzo soil gravel ratio has a benefit on increasing water infiltration, soil water supply, and reducing soil water vaporization.