Abstract: Reticulate red clay is widely distributed in southern China area and common in many kinds of geotechnical engineering. At present, the research of the reticulate red clay mainly focused on the causes and granularity characteristics. The study on its unsaturated characteristics is relatively limited. In this paper, the filter paper method is applied to measure the matrix suction of reticulate red clay in different saturation conditions. Van Genuchten model is used to get the soil-water characteristic curve in drying-wetting process. It is found that due to the small and relatively uniform void, the air entry value of reticulate red clay(about 100 kPa) is relatively larger than that of normal clays. There is no obvious residual stage in its soil-water characteristic curve. The soil water characteristic curve is applied to analyze the stability of one dimensional infinite slope in drying and wetting process. The results indicate that in the same saturation, the slope is more stable in the drying process than in the wetting process. With the increase of depth and saturation, the difference of stability factor in the two processes tends to decrease. Due to the larger contribution of matrix suction, reticulate red clay slope is relatively stable.