Abstract: With the consideration of Gestalt principles in visual cognition,this paper proposed a similarity assessment model which has a comprehensive consideration of point cluster's spatial relationships,spatial distribution and geometry attributes.The topology relationship of point cluster is defined using point cluster's topology neighbors,the direction relationship and distance relationship is defined using point cluster's standard deviation ellipse,and then the computation method of point cluster's topology,direction and distance similarity assessment is given out on this basis.Also the distribution range and the distribution density of point cluster and their similarity assessment method is put forward.Finally the formal five factors were combined to do a whole assessment of point clusters similarity.Experiment results show that the similarity assessment is consistent with intuitive cognition.