To raise the market competition ability of the civil helicopter, it is required to have high technical content in RMS including reliability, maintainability, safety, supportability and testability for the new generation civil helicopter. To meet the requirements of the civil helicopter, it is decided to follow strictly the maintenance matrix from the preliminary design phase of the transmission system. To decrease the maintenance cost, the structure will be optimized during the detail design phase and checked by DMU (Digital Mockup) in VPM (Virtual Product Model) system. And to get the high safety and reliability, some advanced design technical are applied and substantiated by some new test methods. This paper explains design concept application on RMS for tail drive system of the civil helicopter by showing some practice for an example. It can provide the method and reference for the development of civil helicopter transmission system.