Many organizations are familiar with using CRM (Customer relationship management) to manage and enhance the customer relationship. Good customer relationship can bring great benefits and a competitive advantage to organization. And in this era of technology, CRM that consists of eCRM (Electronic customer relationship management) is acknowledged as another potential solution for business.The purpose of this study is to explore what an organization can do to improve the use of eCRM, so eCRM can enhance the customer relationship. In the thesis the authors have studied different eCRM key factors and their relationship in order to improve customer relationship through the use of eCRM.This thesis has used Toyota Mahanakorn, the Toyota dealers in Thailand as a case study for examining the practice of successful eCRM in the organization.Our conclusion is that in order to improve the performance of eCRM, an organization should choose a eCRM technology that suits with organization strategy and practice as well as employees technology and service capabilities.Since this thesis studies the way to improve the use of eCRM in an organization, this thesis will be advantageous to those who plan to implement eCRM in the future and to those who have already implemented eCRM and would like to make it better.