This study aims to determine the value of willingness to pay for commuter line (KRL) users to improve the quality of KRL services and identify determinants of willingness to pay for KRL service users to improve service quality. The method used in this study is a contingent valuation method. In collecting data used the face to face interview method with the Electric Rail Train user. The results of the study show that the average WTP for improving the quality of KRL services is IDR 4,500 (USD 0.32). The cleanliness, comfort, travel time, and income of each KRL user affect the KTP users to improve the quality of KRL services. The result of the study is expected to improve the quality of KRL services, especially in South Tangerang, and can be a reference for managers for public transportation services