Being multifaceted process, implementing customer relationship management (CRM) project has a high risk and uncertainty that must be reduced using planning to get the desirable benefits. As a matter of fact, existing and optimal position must be determined to reduce the gap between them via suitable investment. To identify this gap as well as the way to higher and optimal condition, maturity model can be used. Relying on extended literature, the present paper reviews the existing models and then develops a model for measuring CRM maturity based on CRM critical success factors, CMMI levels and RADAR logic.