This paper deals with the small-signal stability analysis of a dc-distribution electrical power system (EPS) sourced by permanent-magnet synchronous generator (PMSG), which is one of the main topology candidate for future more-electric aircraft (MEA). A detailed mathematical model is developed and comprehensive EPS modal analysis including eigenvalues sensitivity and participation factor performed to investigate the EPS stability and how it is effected by machine and control parameters, and by operating conditions such as the machine speed and load power. Time-domain simulations are carried out to support the theoretical analysis. The detailed analysis in this study delivers to the EPS designers a good insight into EPS properties and ways of appropriate parameters selection at the early design stages.