Abstract: The Chapman-Maxwell method (the CM filter) with recession constant calculated from Automatic Baseflow Identification Technique (ABIT) was used to separate baseflow from daily runoff at the Taonan hydrological station in Taoer River basin．Time series-based rainfall-runoff events were separated to explore runoff event response to precipitation． Annual precipitation, runoff and baseflow were found to show decreasing trends, with abrupt decreases detected in all three．Baseflow was found to maintain continued runoff process, with a total number of 72 events being identified from daily series of streamflow．A strong correlation of the volume of precipitation (P_tot) to maximum runoff (Q_max) and maximum baseflow (Q_Bmax) was observed．Runoff event response to precipitation showed marked threshold characteristics, being affected by soil moisture content and watershed water storage．Runoff process was found to be affected by climate change and human disturbance, therefore linking dynamic hydrological changes to ecological indexes was helpful to protect river ecology．These data will help to understand runoff generation and hydrological connectivity, and provide certain theoretical and practical references to maintain river ecosystem health．