This article introduces the function and feature offered by Dialog On line retrieval system,so as to gain the inforemation as needed and several kinde of means by which reduces search fees.

Based on comparison and analysis of database contents embodied in five international online retrieval systems in subject and its hiberarchy,this paper puts forward five suggestions that would help to select the right online retrieval system on database resources.

4 and the methods of its installation,setting-up and utilization,and through some examples demonstrates several skills of reducing the online retrieval expense.

With the purpose of saving money of the users,this article introduces ingenious use in online retrieval of patents in order to reduce the costs in using the system of DIALOG.