Through statistic analysis of the precursors of 20 earthquakes in the Gansu-Ningxia-Qinghai region,it is found that earthquake precursors in this region have regional characteristics,i.e.anomalous area is small, anomaly amplitude is small, anomaly lasting time is short and seismicity period is short. Furthermore, it is found that the earthquake precursors in this region have following five common characteristics:(1)Seismicity gaps always appear before M≥6 earthquakes and with approaching to earthquake occurrence time, seismicity gaps of different magnitude earthquakes appear subsequently and nestedly from strong events to small ones.The sclerous process of medium of seismogenic zone gradually is emerged.(2) The tendency anomalies of various kinds of precursors have their own dominant patterns.(3) Before an impending strong earthquake the inverse(or accelerating) variation of ground deformation is often appearing precursor in the region.(4) Various precursors in an area have inherent harmonic identity in earthquake developing period.(5) Occurrence time and short-term precursor of a strong earthquake is relevant to some outtide factors such as magnetic storm, moon gravity and atmosphere pressure.