We have been designing and implementing an object-relational multimedia database. A new data model was first developed, which represents various types of media entities, and temporal/logical relationships among these entities. Thereafter, a three-layer object-relational database infrastructure was proposed in our project, in order to support the proposed data model. In this paper, we concentrate on the search and query mechanisms designated for our database infrastructure. In particular, we discuss a new query language, which is developed as a multimedia extension of SQL3. This query language provides a greater expressive power, not only on simple/complex media entities, but also on various relationships among different entities. Consequently, it supports both content-based and structure-based queries. We are currently implementing the query language in our object- relational multimedia database prototype system based on the Illustrar. The fundamental structure of our query language, as well as main features of Object Manager and Query Manager of our prototype system, are also presented in the paper.