Abstract: Vegetation litterfall is one of the important component of forest ecosystem, it plays an important role in maintaining matter cycling and nutrient balancing, conserving water and soil for forest ecosystem.In order to study the moisture content ability of different vegetation litterfall, the author investigated on the spot and taken sample from the typical karst rocky desertification regions in the northwest of Guangxi such as Yizhou county, Huanjiang county , Pingguo county, etc. Through analysis and data statistical on relevant indexs such as exist litterfall amounts, conserving water characteristic and moisture content of soil of different vegetation, we made arrangement for the exist litterfall amounts, maximum water amounts conserved and maximum water rate conserved, soil moisture content of different vegetation form. The order of exist litterfall amounts from maximum value to Minimum value was: Oriental white oak forest, pine forest, mingled forest, Unisexual lily magnolia forest, pine and Tuart mix forest, Tuart forest, Winter Jasmine forest,Cedar forest. The order of the maximum rate of retention was: Cunninghamia lanceolata forest, single Sieboldii forest, Winter Jasmine forest, Oriental white oak forest, Sundry wood, Pine-Eucalyptus mixed forest, Eucalyptus forest plantations of pinus ellottii. The order of the soil water content was : Oriental white oak forest,Sundry wood, plantations of pinus ellottii, Pine-Eucalyptus mixed forest, Liquidambar forest, single Sieboldii forest, Eucalyptus forest,Cunninghamia lanceolata forest. By handling the experiment data and some factors such as economic cost and climate and geography were synthesisly considered, it is pointed out the optimization pattern of vegetation restoration which can improve the water maintenance of the soil, and provided the theory basis for Karst Rocky Desertification Region of ecosystem restoration in the northwest of Guangxi.