沙地开发利用前景评价专家系统（ＬＥＳ）是根据土地资源数据库和有关土地的自然地理属性以及人为活动关系的知识，按照一定的推理机制，自动进行沙地开发利用前景评价。本系统在“三北”温带大陆性干旱气候类型区内蒙磴口县进行实验，按开发利用由易到难共评价出７个等级，１７．８６ｈｍ２。评价结果与实际情况一致。 Based on the database of land resources and the knowledge of the natural geographical attributes and human activities of the land resources database, the LES is to evaluate the development and utilization of the sand land automatically according to a certain reasoning mechanism. This system was tested in Mengxikou County in the “Three Norths” temperate continental arid climate type area. According to the development and utilization, seven grades and 17.86hm2 were evaluated. Evaluation results and the actual situation.