根据植被调查和土壤水分调查资料 ,讨论了黄土丘陵典型地区的造林的水分条件和植被地带的划分。水分不足是造林的限制因子 ,在现有天然林及人工林中普遍存在土壤干层 ,所以 ,延安研究区南部应属干旱森林区 ,北部属森林草原区。并根据土壤水分现状和植被现状 ,进行了植被建设区划 ,其划分两个一级区和两个二级区 According to the data of vegetation survey and soil moisture survey, the afforestation water conditions and division of vegetation zones in typical areas of Loess Hilly area are discussed. Water deficit is a limiting factor for afforestation. Dry soil layers are commonly found in existing natural forests and plantations. Therefore, the southern part of Yan’an Research Area should be arid forest area and the northern part be a forest grassland area. According to the status quo of soil moisture and vegetation status, the division of vegetation construction was divided into two primary areas and two secondary areas