Abstract: Using capillary barrier to protect the slope is one of the effective means to reduce the damage of rainfall-induced landslide. Capillary barrier has a good performance in slope anti-seepage, and can meet the needs of ecological slope protection. According to the research status of capillary barrier, the influence of different factors on capillary barrier and its anti-seepage effect, including geometric structure, internal seepage and the composition of fine/coarse grained materials were analyzed. The advantages and disadvantages of this technique were pointed out. The main improvement measures and ways to enhance the protective performance of capillary barrier were discussed as well. The results show that capillary barrier technology is an important development direction of slop protection and ecological slop protection in the future.