According to gauged discharges in the two representative hydrologic stations of the Shaliguilanke and the Xiehela，this paper uses a statistical method，the Kendall non-parameter tendency test and the wavelet analysis to analyze annual distribution and variation characteristics on the basis of the observations of annual runoff from 1957 to 2006. The result shows that the variation coefficient over years is small and relatively stable.  In order to objectively display this complex wave shape of annual runoff change，this paper introduced the gray topology forecasting method. The results show that the increase trend of the Aksu annual runoff volume is not obvious in the next five years.