Abstract: Nondeterminacy relation’s reasoning between geometrical bodies in the geometrical space is the main research direction of spatial reasoning. First, the conceptions of the features and main feature in one geometrical body are given and it is proved that the relations between the features can substitute the classical spatial relations. Second, adjacent relations, parallel relations, substitution relations, common line relations, and linear relations are introduced to describe the relations between the main features. And these relations are fuzzified with membership functions. Finally, a kind of spatial fuzzy reasoning is put forward, and an example is also given, which shows the method is effective.