对广西南宁市郊尾叶桉人工林及灌草坡 0～ 1 0 0cm深土壤物理性质对比测定的结果表明 :林地土壤容量为 1 37～ 1 47g/cm3,比灌草坡 1 5 0～ 1 6 2g/cm3分别低0 1 2～ 0 1 9g/cm3.平均总孔隙度、平均通气度、平均最大持水量和平均渗透速度依次为 45 0 % ,2 1 4% ,435 7mm和 1 3mm/min ,分别比灌草坡高 3 4% ,3 4% ,1 9 9mm和 0 2 8mm/min ,随土壤深度的增加 ,林地与灌草坡各参数的差值逐渐减小 .尾叶桉人工林取代灌草植被后 ,对改良土壤结构 ,提高土壤蓄水保水能力都具有良好的水文生态功能 The results of soil physical properties of Eucalyptus urophylla × Eucalyptus urophylla × Eucalyptus urophylla × Eucalyptus plantation and shrub-grass slope in the suburbs of Nanning, Guangxi Province, were compared. The results showed that the soil volume of forest land was 37 ~ 147g / cm 3, which was 150 ~ 16 2g / cm3, respectively, from 0 1 2 to 0 1 9g / cm3.The average total porosity, average air permeability, average maximum water holding capacity and average infiltration speed were 45 0%, 21 4%, 435 7mm and 13 mm / min , Respectively, which were 34%, 34%, 139mm and 0 28mm / min higher than that of shrub and grassland, respectively. With the increase of soil depth, the difference of each parameter of forestland and shrub-grassland gradually decreased. After replacing the shrub and grass vegetation, it has good hydrological and ecological functions for improving soil structure and improving soil water storage and water retention capacity