Abstract: A urban municipal supervision and management grid system is implemented based on spatial databases.In this system,urban municipal supervision and management area is divided into many continuous anomalistic grids.The establishments in the grid are called components,and the accidents are called events.Then an appointed person will fully take charge of each grid area.The person should go the rounds and report in due course to the functionary once a paroxysmal event happens in the grid area.The grid plot is easy to draw with the ordinary cartography technology.While the whole grid system is hard to evaluate its suitability.Trying to achieve the evaluation,six variables and a model are presented.The six variables are: impactful area(A),time per patrol(T);short-time increase area(S);long-time increase area(L);grid comvex corner number(V);components occupancy percent(P).Based on the six variables,a hierarchical statistics model is built to achieve the evaluation.The model can find an idiographic statistic to show the suitability of a grid system.And the difference cities can be compared by the statistic.Finally,the model's maneuverability is proved by SPSS software and the material data is from Shenzhen urban municipal supervision grid division.The example shows that the hierarchical statistics model works well.