In this paper, a State-Based Dynamic Transportation Network (SBDTN) model is presented, which can be used to describe the spatiotemporal aspect of temporally variable transportation networks. The basic idea of this model is to associate a temporal attribute to every node or edge of the graph system so that state changes (such as traffic jams and blockages caused by temporary constructions) and topology changes (such as insertion and deletion of nodes or edges) can be expressed. Since the changes of the graph system are discrete, the temporal attribute can be expressed as a series of temporal units and each temporal unit describes one single state of the node or edge during a certain period of time. The data model is given as a collection of data types and operations which can be plugged as attribute types into a DBMS to obtain a complete data model and query language. Keywords. Spatio-temporal, Database, Moving Object, Algebra.