Huajiang Valley is a karst gorge of serious stony-desertification.The moisture is the main restriction factor of plant growth in Huajiang Valley.So to choose the appropriate vegetation type to fully utilize precipitation and prevent soil erosion is an important element in the Huangjiang Valley district.The spatial and temporal distribution character of soil moisture under the different vegetation in Huajiang Valley is studied in this article.And the right plant type which can be more beneficial to ecological balance and conserve water and soil is also discussed.The results show that not only on the spatial distribution,but also on the temporal distribution,the Chinese prickly ash has the best efficacy to converse water and soil.In a word,the Chinese prickly ash can improve the ecological and economic benefits of Huajiang Valley.