该文给出了泥石流防治的流域自然地理环境优化效益的定义，阐述了流域自然地理环境优化的过程，并分析了流域自然地理环境优化效益与其它有关泥石流防治效益之间的关系，流域自然地理环境优化效益包括减灾效益、减洪效益和减沙效益三大部分，每种效益由若干指标构成。文章给出了流域自然地理环境优化的指标体系，并对１０种优化效益指标作了初步探讨。 This paper gives the definition of optimization benefit of natural and geographical environment of debris flow prevention and control, expounds the process of natural geographical environment optimization, and analyzes the relationship between the optimal benefit of natural geographical environment and other related debris flow prevention and control benefits. Environmental optimization benefits include the benefits of disaster reduction, flood control benefit and sediment reduction benefit of three parts, each benefit from a number of indicators. The article gives the index system of the optimization of the natural geographical environment of the river basin, and makes a preliminary discussion on the 10 kinds of indexes for optimizing the economic benefits.