Typical vibration characteristics for resonance,half speed whirl(critical half speed whirl),double low frequencies,gas whip,power frequency rubbing and low frequency rubbing were given under gas bearing rotor system for a single span.Typical vibration characteristics as mentioned above were analyzed by axis center tracks,bifurcation and spectral analysis.Qualitative theoretical analysis and corresponding vibrational controlling methods were discussed with equation of motion for bearing rotor system,which provides vibration controlling methods and typical vibrational data for gas bearing rotor system stability study.