Abstract: This paper presents a cadastral spatial data storage structure based on relational database, and the procedure of its realization.This paper consists of three parts.In the first part, some existing problems in old cadastral spatial data storage structure are discussed.These problems include:①the security of cadastral spatial data is difficult to be assured of;②the change of cadaster is difficult and the integrality of cadaster is difficult to be assured of;③ there exist in some problem transmission of cadastral information and its share;④ the efficiency of data access is low.In the second part, the feasibility of using relational database to store spatial data is analyzed and a new cadastral spatial data storage structure is presented.At the same time, the related table structures and its field descriptions are given, the merits and demerits of this storage structure are analyzed in detail.In the last part, through a real example, the detailed method to make the new storage structure realized are given.Moreover, some key techniques to make the new storage structure realized are discussed.These techniques include:①the application of database transaction;② the application of database trigger;③the secure recovery of database.