Abstract: Provides a logical design approach for object-oriented database, and an example on logical design for object-oriented database is proposed to examine the availability of the approach.The approach extends the traditional E-R diagram in which it includes inheritance, aggregation. message and method. The approach tells the way to get the Extended E-R Diagram from source text which tells the requirement. The way is made up of steps:concept selection, concept analysis, formalize, and conceptual model affirming.