In order to reveal the variation characteristics of annual and interannual runoff in Danhe River Basin, according to the monthly average flow data in Shanluping hydrological station from 1955 to 2000, the paper used Gene coefficient and concentration degree (period) to study the Dan River runoff distribution in a year; and applied Kendall test and R/S analysis methods to analyze the annual, flood and non-flood season runoff variation trends, and used Morlet wavelet to identify these runoff sequences' various cycles. The result showed that during the period of 1955 to 2000, The allocation of annual runoff in Danhe River basin was fairly well-distributed, and the curves mainly belonged to double peak type in each period.The maximum runoff occurred in August. The runoff sequences of annual, flood season and non-flood season presented significant decreasing trend, and the future decrease process had a certain anti-sustainability. The runoff sequences in flood season and annual had similar wet-dry alternating cycles, including change main cycles of 4, 10 and 15 years;The runoff sequence in non flood season have wet-dry alternately various cycles of 15 and 28 years.