由于现实世界的连续性和多样性，地理实体具有不确定空间分布范围和边界，它们在GIS中的表达被称为模糊目标，提出了“模糊空间分布目标”的概念表示模糊目标即地理实体的复杂性和多样性。讨论了3个通用模糊目标模型以适用于不同的情形,FF－object具有模糊空间分布和模糊内核，适用于描述空间重叠的目标；FG－object具有确切内核和模糊空间分布，适用于描述空间分离但边界不明的目标，CF－object具有确切的条件边界和模糊内核，适用于描述空间分离且有边界的目标，我们用一个海岸带研究的实例说明模糊目标模型的应用。

The entities in reality usually have indeterminate boundary and distribute continuously over space. They are fuzzy objects and cannot be represented by conventional field-oriented or object-oriented models in GISs. The authors propose the concept of“objects with fuzzy extents”to represent them. Three fuzzy object models are developed to represent fuzzy objects for different situations. The Fuzzy-Fuzzy object（FF-object）model represents objects that have an uncertain thematic description and an uncertain spatial extent，these objects may spatially overlap each other. The Fuzzy-Crisp object（ FC-object）model represents objects with and uncertain spatial extent but a determined thematic content and the Crisp-Fuzzy object（CF-object）model represents objects with a crisp boundary but uncertain content. A practical example of coastal geomorphology study is elaborated to demonstrate the practical use of the proposed concepts and models.