Soil desiccation on artificial forestlands is increasingly threatening the achievements and effects of artificial vegetation constructions of the loess plateau. Based on widely observations of deep soil moisture on 23 kinds of tree and shrub forestlands, which included apple tree (Malus domestica Borkh),black locust tree (Robinia pseudoacia), Chinese pine tree (Pinus tabulaeformis Carr.), Manchurian oak tree (Quercus liaotungensis), David′s mountain laurel shrub (Sophora viciifolia), seabuckthorn shrub (Hippophae rhammoides) and littleleaf peashrub (Caragana microphylla), at different growth locations and in different growth ages on 3 vegetation zones of the Loess Plateau, soil water amounts, soil water distributions and soil desiccation intensities on various forestlands were compared and analyzed, effects of soil desiccation of different forestlands were quantitatively assessed. The results show as following: (A) Average soil moistures, soil water storages and available soil water storages in 0-1000 cm soil layers of 23 forestlands were 10.84％, 1409.8mm and 446.6mm respectively, which were obviously lower than local natural grasslands and soil stable moisture, and soil water overuse amounts was higher than 500mm and annual soil water overuse was 36.8mm. Soil water overuse amounts and speeds on middle semi-arid forest-steppe zone was the highest one and south semi-humid forest zone was the lowest one in 3 vegetation zones. Sequences of soil desiccation speeds of forestlands from high to slow were littleleaf peashrub and David′s mountain laurel shrub, Chinese pine tree, black locust tree and seabuckthorn shrub, apple tree and Manchurian oak tree. (B) Except young apple tree, seabuckthorn shrub and littleleaf peashrub land, soil moistures beneath 300 cm soil layers on all other forestlands were obviously lower than natural grasslands and local soil stable moisture, and soil moisture of south slope forestlands were lower than north slope forestlands, and slope forestlands were lower than that highlands. Maximum soil water use depth of forestlands were close to or over 1000 cm. soil moistures on deep soil layers of forestlands decreased and thickness of desiccated soil layers increased as forest growth age increased. (C) Average soil desiccation index of 23 forestlands was 51.6％,soil desiccation intensity was medium desiccated (prone to serious desiccated). Thicknesses of desiccated soil layers on forestlands reached or passed 800 cm, and soil desiccation intensities strengthened and thicknesses of desiccated soil layers deepened as rainfall decreased from south semi-humid zone to north semi-arid prone drought zone. Sequences of soil desiccation intensities and desiccated soil layer thicknesses of forestlands from high to low were Chinese pine tree, Manchurian oak tree and littleleaf peashrub firstly, black locust tree secondly, apple tree and seabuckthorn shrub lastly.