A number of algorithms of clustering spatial data for diminishing the number of disk seeks required to process spatial queries have been developed. There have been two approaches to clustering spatial data: object clustering and page ordering. Object clustering is to store spatially adjacent objects at the same pages(or multi-page cluster) to reduce the number of page accesses, Page ordering is concerned with the order of pages in one-dimensional storage for storing two-dimensional spatial data to reduce the number of disk seeks. Previous works related to page ordering have only used the space filling curves, especially the hilbert curves. Page ordering based on the space filling curves does not take into account the uneven distribution of spatial objects and the types of spatial queries. In this paper we develop a cost model to define the page ordering problem based on performance measurement and then find out the method of page ordering for processing region queries in static databases. We make use of the method of simulated annealing as an optimization heuristic. The experimental results demonstrate that the newly proposed ordering method can achieve considerable improvement in its performance. The main contribution of this work is the cost model of the page order, from which we could estimate the number of disk seeks for processing region queries.