The characteristics of wheel-rail coupled vibration are of great significance to the design of vehicle system and the matching of vehicle and track. Therefore， based on the modal superposition method and eigenvalue algorithm， this paper proposes a method to calculate the natural frequencies of the coupled wheel-rail system and analyzes the influence of the system parameters on the vibration characteristics of coupled wheel-rail system. Results show that pin-pin resonance in the track system is easy to be found when the rail is discretely supported， while there is no obvious pin-pin resonance phenomenon when the rail is continuously supported. The pin-pin resonance frequency is proportional to the bending stiffness of the rail and inversely proportional to the vibration mass of track and the span of the fastener. The wheel-rail resonance is the coupled vibration of the wheelset and the rail on the elastic foundation of track， in which the frequency is significantly lower than the natural frequency of the track. The system parameters have a greater influence on the wheel-rail resonance frequency， and it increases with the mass of the wheelset and decrease with the equivalent stiffness of the fastener. The wheel/rail resonance frequency increase obviously， once the frequency-dependent stiffness of fastener is considered. The short-wave irregularity will induce wheel-rail resonance and worsen the wheel-rail interaction. Tested results reveal that the resonance speed is 23~68 km/h when the wavelength vary from 100 to 300?mm.