To optimize networks and database systems for promotion of the industry technology development contributing to the solution of the global environmental problem, studies are made on reusable information resource and its utilization methods. As reusable information resource, there are external database and network system for researchers` information exchange and for computer use. The external database includes commercial database and academic database. As commercial database, 6 agents and 13 service systems are selected. As academic database, there are NACSIS-IR and the database which is connected with INTERNET in the U.S. These are used in connection with the UNIX academic research network called INTERNET. For connection with INTERNET, a commercial UNIX network service called IIJ which starts service in April 1993 can be used. However, personal computer communication network is used for the time being. 6 figs., 4 tabs.