Abstract: The similarity measurement of spatial relations is the foundation of some many application problems in geographic information science,for example,it is an important restriction to keep the consistency of spatial relations before and after the cartographic generalization.In this paper with the adjacency relation similarity of building group as the research object,and on the basis of Delaunay triangulation network and Voronoi diagram with the tools,based on the similarity theory,establishes two kinds of similarity models to use for quantifying calculation and estimatinge of adjacency relation,including the similarity models of adjacency relation based on the same characteristic value and the similarity model of adjacency relation based on the iso-distance-relationship contour.