Abstract. In this paper, an analysis of the schema evolution process in object oriented databases is made using an object oriented data model that supports temporal features and versions definition -the Temporal Versions Model. A meta schema structure is defined to store information concerning to evolutionary schema states, as well as their classes, attributes and relationships. An implementation proposal is presented, combining specification and manipulation mechanisms including version and time concepts. Two alternatives are defined for the database extension management: multi-pool for schema versioning and single-pool for class versioning. Concerning the physical representation, both approaches can be used in the same application.