Abstract: To overcome such limitations,the gravitational theory is firstly employed to describe the issue of spatial clustering,where a force for spatial clustering,called aggregation force,is developed.Further,a spatial clustering validity index based gravitational theory(SCV for short) is proposed.Through the experiments on both simulated data set and real-world data set,it can be found that the index developed in this paper can well evaluate the spatial hard clustering scheme including both arbitrary shape clusters and outliers.The comparative experiment is made to further demonstrate the SCV index superior than classic Dunn index.