Abstract: The former Soviet Union scholar Borodin(Бородин) has suggested a map object selection principle which can consider the object importance(e.g.the river length) and the density of object distribution(e.g.the distance between the adjacent rivers) simultaneously.But no concrete algorithm for implementation has been given by Borodin.Scholar of China,Zhu Guorui has suggested an excellent method for implementing the Borodin's principle and named this method as Method of Geometric Sequences.The main intentions of this study is to state the mathematic foundation of creating the density control table of map object selection,to found the essence of Difference Geometric Sequences of Borodin's principle,to generate a more simpler algorithm and to discover some intrinsic laws of structure of matrix elements.