Abstract: The formal model of spatial directional relations is one of the most important parts in spatial relation research.To achieve high generality and practicability,a quadtree histogram model is proposed in this paper.The characteristics and defects of present models are first analyzed and then the basic idea and construction method of quadtree histogram are proposed in detail.Finally a new method to judge spatial directional relations based on quadtree histogram is described.Excellent experimental results from synthetic image examples show that this model is feasible.