AbstractData representation and management in the image database system are discussed. It is pointed out first that both efficiency of representation (amount of data) and the efficiency of processing and retrieval are important in the representation and management of data. From this viewpoint, various kinds of image and graphics representations are discussed, arriving at the viewpoint of “management of M‐dimensional data in N‐dimensional space.” The point data (0 in N data) and the N‐dimensional image data (N in N data) are considered. Various kinds of data structures such as KD tree, KDB tree, 2N partition tree and linear tree, are discussed and analyzed from the viewpoint of the preceding two characteristics. Especially, a tree‐type data structure (called BD tree) is proposed where the N‐dimensional rectangular region is used as the partition key. The structure and the performance are discussed indicating that the performance is better than in other structures. Examples of applications of the proposed data structure in the image database are discussed, as well as the possibilities of future