In order to make clear the relationship between coal mining and runoff reduction or even drying-up of the Kuye River, China, we analyzed the variation characteristics of runoff with the daily runoff data and related hydrometeorology data from 1953 to 2010 of the Wenjiachuan station, a control hydrological station at the Kuye River. Then, the impacts of coal mining on surface runoff are quantitative simulated by using monthly water balance model of the Yellow River. The results indicate that the measured runoff data generally present a phase-decreasing trend over the last 60 years with turning points in 1979 and 1999. The runoff reduction ratio due to human activities was 39.44％ during the period from 1979 to 1998, and it quickly increased to 56.50％ during the period from 1999 to 2010, in which the annual average runoff value affected by coal mining reached 29.69 mm, which is equivalent to approximately 2.58×10⁸m³／year. That is, human activities have become the dominant factor causing reduction of surface runoff in the Kuye River.