中文摘要：

沟沿线是黄土高原地区地貌类型、土地类型及土地利用类型划分的基本分界线。在提出了沟沿线划分的基本原则的基础上，根据沟沿线的成因、空间分布、形态、数量、显著性、发展速度、扩展方式的差异为基本依据，充分研究黄土高原侵蚀机理与过程，结合大量的遥感判读与野外工作，提出了黄土地貌沟沿线类型划分体系。并进一步分析在黄土地貌水蚀沟谷不同发育阶段中沟沿线类型的变异，其结果也进一步体现出沟沿线发育的特点以及与黄土地貌沟谷发育的密切联系。

英文摘要：

China loess plateau is world-wide famous for its peculiar and unique landscape, in which the loess shoulder-lines zigzag on the surface making a distinct separation between loess positive terrain with the negative one. More evidences from both field investigation and quantificational analysis show that the shape and spatial distribution of loess shoulder-line could be regarded as an effective clue to make a deep study of loess landform. However, there are very few works was done on loess shoulder-line. In this paper, on the basis of carefully study about the loess erosion process, and a lot of field work with remote sensing imagines, three important classifying principles are brought out. Taking seven main aspects from different view point （cause of formation, spatial distribution, configuration, quantity, distinct character, development speed, expand mode） into consideration, in addition to the principles, a systematic classification of valley shoulder line is put forward, meanwhile some necessary explana- tions and illustrations are also given. For example, abiding the spatial distribution pattern principle, shoulder line could be divided into four basic types： parallel pattern, branch pattern, skew pattern, separate pattern. Furthermore, the classification variation of the shoulder line in different phases of the gully development is carefully studied, thought which the close relationship between the shoulder line and the loess relief is presented clearly. On one hand , along with the development of stream network, shoulder line extend itself in the drainage area and the type vary correspondingly; on the other hand, a specific type of a shoulder line is the representation of gully development phases. The classification result will be very useful in the further study of loess relief and shoulder line itself. The classification is the cognition of loess shoulder-line from different view point, and is the basis for constructing an overall concept of loess shoulder-line. This study is of great significance i