A certain number and significant across-fault short leveling deformation anomaly were observed in the source region around a dozen hundred km range before Yumen MS5.9 earthquake in 2002,Minle MS6.1 and MS5.8 earthquakes in 2003 and Minxian MS5.2 earthquake in 2003.The main abnormal morphology were acceleration,sudden jump or sharp point sudden jump,with mid-term background or short-term precursors significant.Anomalies reflect that the fault first enhanced inverse then changed to relaxation,earthquakes usually happened when the fault change relaxation.The spatial distribution and occurrence time of anomaly have added and confirmed significance to precursor anomalies of fixed-points.