On the basis of analysis of the radon data recorded by single station

the short-impending period anomalies of earthquakes with M≥5. 0 in the area between Qilian Mountain and the Hexi Corridor are statistically analyzed in the paper. These include anomaly frequency

duration

the interval from the ceassion of anomalies to earthquake occurrence

the anomalous area

especially the short-impending earthquake prediction items of precursory anomalies in the studied area. By analyzing 8 typical earthquakes

it is shown that the short-impending characteristics of precursory anomalies of radon in ground water before strong earthquakes in the studied area are as follows: （1）The main shape of the short-impending precursory anomaly of radon is jump-descending variation

and the precursory amplitude values are large. （2）The earliest time of the short-impending anomaly beginning is 3 moths and 20 days

especially 2-40 days before the earthquake. The anomaly process is undulatory

synchronizing and group or coupled. （3）The characters of short-impending precursory field are changed with the earthquake epicenters in the studied area. The main anomaly is near field in 400 km in middle-east segment of Qilian Mountain

which shows that the anomalies are migrated from outer to the focus in 40-390 km; but in west segment of Qilian Mountain

the main anomaly is far field beyond 400 km and the migration is not obvious. And this help to predict the earthquake epicenter.（4）The earthquakes occurred after 15- 80 days when the short-impending anomalies stopped. Some occurred when the anomalies were at turning points or just before stopping

the fewer occurred when the anomalies were changing.