The procedures of the study are mainly through the review on the relevant reference documents related to the subject of those have been published domestically and internationally, meanwhile to get a better understanding on the most recent development on Information Technology and its associated models which are being applied to the customer relationship management by the organizations and/or business units in the world. Then, through the investigation and review on steel industries to understand the real situations domestically and internationally, specifically to focus on the Sheng Yu Steel Co., Ltd. As an example, for which to plan the implementation of Extranet System for the improvement of Customer Relationship Management (CRM) by using Information Technology, what problems it will be faced and how is the best strategyfor this implementation. Then after the completion of the study, to make a constructive recommendation to the Sheng Yu Steel Co., Ltd as an useful reference when the Extranet system to be planned and implementedfor. In Chapter-1 ¡©Introduction¡ª¡Ato descibe the backgroud, purposes, procedures and the limitation related to the study¡Fin Chapter-2, the major is concentrate on the review and understand on the relevant documents of the subject related¡Fin Chapter-3, specifically to focus on the existing situations of the steel industries and the Sheng Yu Steel Co., Ltd. how it is the current situation to the subject issue¡Fin Chapter-4, to have further investigation on recent situations for the use of Information Technology in Sheng Yu Steel Co., Ltd. to make a recommendation for their reference whn they plan for the implementation of Extranet System for the improvement of Customer Relationship Management¡Fand finally, in Chapter-5, to describe the findings and issues for whicht to be expected to have further study in the future to come up a generalized model for which can be applied to all companies not only for steel industies but also to all conventional enpterprises as an important and valuable reference guideline.