Abstract: The key technology of progressive transmission for vector map is the successive multiple representations of spatial data to form the map data to line-structure organization in the server. The paper aims at vector contour data offering a new progressive transmission model based on Fourier series which has the properties of multiple representations. The corresponding relation between map scale and the number of Fourier series expanded-item is discussed, and the Fourier descriptor model for curve with multi-scale representation can be built with the relationship on the server site. The Fourier descriptor components for different map scale will be available gradually and curves will be rebuilt with them on the browser site, so the progressive transmission and representation for contours can be achieved. The actual application of model has two main characteristics. First, what is transmitted in the network is feature vectors extracted from curves, which played a important role in data compression, rather than coordinate data of curves; second, continuous map scale representation can be achieved with the model.