Abstract: Selecting Ymluoxia station's runoff data from the 1944 to 2004 and Shule river station's runoff data from the 1953 to 1999,we analyze the persistence,the periodicity and the annual variety of the flow in inland river in Hexi regions of Cansu in the past 50 years and its response to the abnormity in the surface heat intension on tibetan plateau. The result shows that water resources of the middle and the west of Cansu corridor have good persistence,especially in fall and winter. There is good correlation between water resources of the middle and the west of Cansu corridor and the surface heat intension on tibetan plateau. The early circurnfluence characteristics can forecast the runoff of late May. Xinjiang ridge is weaker,Fast Asia trough is shallower, precipitation and flow is increasing;and vice versa. Runoff forecast can be used as the Northwest drought forecasting virtually.