The object oriented method becomes very popular in software development because of its efficiency of automating software development processes and reusing software modules. To date, various object-oriented CASE tools have been used, however, they have concentrated on providing tools for developing a software system within a geographically local area. Even though we can use a general purpose CSCW tool for the cooperative software development in distributed environment, cur rent CSCW systems do not support any efficient object-oriented software development method. This paper discusses the ways of combining CSCW features with an object-oriented CASE tool by introducing the experimental distributed object-oriented software development environment, DOOD(Distributed Object-Oriented Designer). DOOD supports three models (object model, dynamic model, functional model) of OMT(Object Modeling Technique) and provides consistent and transparent user interfaces for minimizing effects of geographically dispersed developing environment. Our system is implemented based on a client-server architecture. DOOD/Server manages the communication among clients and guarantees concur rent and consistent accesses to all the objects in the central repository. DOOD/Client provides modeling and collaboration schemes over TCP/IP network