Summary form only given. As the first step of database integration, a participating local database schema should be transformed into an abstract one to remove data model conflicts. For our project, the object-oriented schema is chosen to represent the integrated information and a semi-automatic method is developed to transform relational schemas into OO schemas. The main idea behind this method is to define two kinds of logics: a relational database logic L/sub db/ and an object-oriented logic L/sub o/ to formalize the corresponding data models. L/sub db/ is used to model a database structure as well as its state, while L/sub o/ is utilized for an object-oriented database. Then, based on these formalisms, a set of Horn-clause-like rules is constructed to perform meta-level reasoning for translating a formalism into another.