Because of strong competition, fragmentation of markets, short life cycles of products and increasing customer awareness and complexity, the necessity of relationship marketing approach is felt more than ever. Relationship marketing involves creating, maintaining, and enhancing strong relationships with customers and other stakeholders. A relationship orientation implies that the focus of marketing is on retaining customers by maintaining and strengthening win-win relationships over time. Relationship marketing is more about maintaining existing customers than to attract new customers and it is just in contrast to the transactional marketing. This article first describes the concept of relationship marketing and views it from two American and European perspective. The reason for emergence of relationship marketing and its historical roots is presented and finally the most important relationship marketing models which are presented by various experts has been analyzed. Organizations and companies, using relationship marketing approach can gain competitive advantages and increase customer satisfaction and loyalty. Since customer retention, loyalty and satisfaction are crucial to survive business, so today using an approach that better achieves these goals is highly regarded. Relationship marketing as a new approach has proven in theory and practice that it is one of the most successful approaches.