Abstract: According to definition of geo-data model, it has been analyzed that time is a basic property of geographic entity and how to study geographic time in GIS. In the case of reality geographical environment changing fastly and application focusing on analysis of local change, current geo-data model have many flaws such as redundant storage of unchanged data、difficult extraction of temporal information、implicit representation of temporal property of geographic entity. Based on the law of existing many synchronous changing small units, a temporal geo-data model with timestamp on the group of synchronous changing data items and the segmented topological arc is presented, which reduces redundant storage and shows us apparent temporal property of geographic entity.