Abstract: At present, objects may be located on Corba (Common Object Request Broker Architecture [14]) platforms using either the naming service [15] or the trading service [17], both standardized by OMG (Object Management Group). By associating a name to a Corba object, the naming service helps users in retrieving a particular object managed by a remote server. The trading service allows, on its own, to localize objects according to the properties they have exported to the trader. Directory services, and particularly LDAP (Lightweight Directory Access Protocol [19]), the most famous directory in the world of the Internet, combine features provided by naming and trading services. Directory services provide advanced features to query directory entries on their names and/or their properties. This paper proposes a Directory Service relying on the LDAP naming model, adapted to the management of dynamic Corba objects, that is objects frequently updated. The directory service also proposes query facilities and a query evaluation model adapted to the management of distribution and possible failures induced by the integration of Corba objects in directories.