Abstract: Object-oriented information extraction method has become the mainstream of automatic extraction of information in remote sensing, since it is in accord with artificial intelligence and has more approaches to geographic theories. Objectification is a key step in object-oriented automatic extraction of information, in which a segmentation image is transmitted into a vector image. The proposed method is able to assign a unique value to an object represented by a grey value in the segmentation image, at the same time, calculates some other features of this object. Using this method, many processes such as removing small region, pretreatment of vectorization can be achieved much faster.