金沙江干热河谷地区是我国生态环境脆弱地区之一 ,土壤退化十分严重。探讨该区土壤退化机理 ,对于有效防治土壤退化 ,尽快恢复生态和合理开发该区有重要意义。着重研究了该区母质类型和特性及对土壤退化的影响。结果表明 :1 该区强烈反差的岩土特性和母质层次组构 ,控制了所发育土壤退化发生的区域分布 ;2 不同岩性母质发育土壤的退化指数 (SDI)差异较大 ,体现了母质岩性对土壤退化的主导作用 ,是土壤退化的关键性因素 The Jinsha River dry-hot valley is one of the ecologically fragile areas in our country, and soil degradation is very serious. Studying the mechanism of soil degradation in this area is of great significance for the effective prevention and control of soil degradation, the restoration of ecology as soon as possible and the rational development of this area. Emphasis is placed on the types and characteristics of parent material in the area and its impact on soil degradation. The results show that: (1) The strongly contrasting geotechnical characteristics and parental hierarchical organization control the regional distribution of soil degeneration; (2) the degeneration index (SDI) of soils derived from different lithological parental materials are quite different, The dominant role of sex on soil degradation is a key factor in soil degradation