Service quality is very important in increasing the satisfaction and loyalty of passengers train in Indonesia. The Indonesian Railway company (PT KAI) transformation towards customer-oriented, customer-centric, and e-channel, in this case, is to provide the best service to its passengers. This research was conducted using the Exploratory Factor Analysis (EFA) method to explore service indicators suitable for economy-premium trains in Indonesia and also the Importance-Performance Analysis (IPA) method to be able to identify priority service indicators to be improved by PT KAI. Online questionnaires were distributed to collect primary data by determining the sample using a judgment sampling method. The results of the study found that the majority of respondents were passengers under 35 years old that have a trip with an economy-premium train for recreational purposes/visiting family. The EFA results reduce the indicators from 67 indicators to 43 indicators with 9 variables, namely: train staff professionalism, seating factors, comfort assurance, reliability, food factors, cabin space facilities, accessibility, ticket price factors, and information and technology facilities. The IPA results found 2 indicators in quadrant IV of the Cartesian diagram that PT KAI prioritized for improvement, namely internet access during the trip and cabin space facilities in the form of TV show content and legroom on chairs.