Abstract: Not one of quota model and structure model can be omitted for the selection of cartographic objects in cartographic generalization of computer-assisted cartography and the expert system in map-database.Under the control of the quota,structure model can be used for selecting concrete object.But it muse be considered that a lot of factors act as role in the selection of the concrete objects.Since the relationships of them are generally veiled and arc of universal fazziness,it is either complication or loss of more cartographic imformation to process them with tranditional two-value logic method.In this article,as an example of the selection of rivers,it is initially discussed to use fuzzy sets theory for establishing the structure model of the selection of cartographic objects and it is simply explained to use a simple sample.