Based on the observed precipitation and temperature data at 8 the meteorological stations in the Huaihe River Basin from 1959 to 2008, 25 climate scenarios were established by changing the precipitation and temperature. SWIM hydrological model was used to simulate the runoff under the different scenarios. An analysis was also made on the sensitivity of the ruoff to different climatic elements change in the Huaihe River upstream . The results show that: in the Huaihe River upstream, the impact of precipitationon runoff is bigger,if only consideringthe precipitation and temperature, the sensitivity coefficient of runoff to precipitation change is in the range of 1.7012 ~2.1358, and the sensitivity of temperature variation is weak, the sensitivity coefficient of the runoff at the three stations to the temperature variation is in the range of -0.0499~0.1547; In the study area during the study period, the contribution of precipitation variation to runoff change is small. The contribution values are -0.0014, -0.0052. -0.0009 from the Dapoling Station to downstream. The contribution of temperature change to runoff change is larger. The contribution values are 0.0828, 0.0152, 0.0039 from the Dapoling Station to downstream. The runoff response to climate change is not only affected by its sensitivity to climate change, but also by the variation range of climatic elements.