Abstract:[Objective] The trend, fluctuation and change cycle of runoff and sediment discharge at Datong hydrometric station were analyzed in order to reveal its characteristics of long time series, which were expected to further provide theoretical basis for the development and evolution of estuarine delta.[Methods] Using Mann-Kendall test, Pettitt change point, Mexican Hat wavelet transform methods, the characteristics of runoff and sediment discharge were analyzed at Datong station in the past 60 years.[Results] The results showed that there was no significant change trend in the mean annual runoff at Datong station, while the inter-annual fluctuation was large and annual distribution was uneven. Repeated periodic oscillations were presented in the runoff series, the major cycle periods of the time series were about 6 and 44 years, respectively. Furthermore, sediment discharge had been declined obviously over the past 60 years and its annual distribution was uneven. There existed significant hopping site in the mean annual sediment discharge. In 2002, the hopping site of step down was first grade, the second grade was in 1984 and the third grades were in 1968 and in 1991. Repeated periodic oscillations also existed in the sediment discharge series, the major cycle periods of the time series were about 12 and 30 years, respectively.[Conclusion] There were no obvious trend and abrupt change of annual runoff at Datong station, but periodicity existed to some extent. There was a significant downward trend of annual sediment transport with obvious periodicity and abrupt change.