Abstract: Study on the precipitation variation features for the valley s of the Songhuajiang and Liaohe rivers is undertaken by means of a t rend analysis, power spectral method and wavelet transform in terms of the monthly and seasonal precipitation data from 1881 to 2002.Results indicate that a remarkable interdecadal variation is inherent in the precipitation of the target region, dominated by 27-30 (35-38)year periods for the rainfall in the Song hua jiang (Liaohe)valleys.Based on the evolution of the rainfall itself and auto-regression estimationitis inferred that the former (latter)w ill remain in a drier (a still longer rain-deficient)stage in 5-10 years to follow.