Some GIS's begin to adopt implicit topology description. This approach makes easy to manage temporal data and to fuse several different sources data. However, this approach has not been leading methodology, because it needs much computational time. Recently, computer power make rapid progress, then implicit topology description becomes practicable. The most basic operations in implicit topology GIS is to find logically connecting lines at network node. Based on this operation, for example, region shape restoration and shortest path calculation can be done. This paper proposes an implicit topology GIS model, shows several basic spatial topological processing and evaluates the processing time by experiment. Then, conclude implicit topology description model is applicable for practical GIS on today's PC.
