Multi-scale representations for geographical entities is one of the research focuses in the field of multi-scale spatial database. Compared with the traditional GIS model

the essential modeling mechanism and strategies for building a multi-scale data model are explored. Taken the road feature as an example

a detailed description of multi-representatlon elements in the model are provided. This model includes abstract data types and attribute-value domains for geographical features at different scales

as well as the scale

semantic

and mapping hierarchical relations among features. An appropriate multi-scale conceptual model is given in detail with the multi-scale extended E-R method.