Abstract: 【Objective】 A quantitative research on the response status of wheat - rice double cropping system to the climate change in Huaihe watershed was made in order to make scientific evaluation for improving the breed and cropping system, supply a basis for formulating a reliable and scientific planting system according to the local conditions. 【Method】 The suitability of temperature, precipitation, sunshine and climate for wheat - rice double cropping system in Huaihe watershed was studied by applying the ecological theory of niche-fitness and fuzzy mathematics methods, then the climate suitability function for the crops was established combined with the method of spatial interpolation. 【Result】 The climate suitability of wheat - rice double cropping system showed a downward trend, temperature suitability showed a rising trend, precipitation and sunshine suitability of fitness showed a decreasing trend. The space distribution of climate suitability in Huaihe watershed wheat - rice double cropping system is decreasing from the southeast coast areas and plains to the western mountain areas. In the future climate change scenarios, the Huaihe watershed wheat - rice double cropping system, climate suitability will increase, but little change in spatial pattern. 【Conclusion】 The climate suitability of the wheat-rice double cropping system in Huaihe Watershed had apparent response to the global warming in recent decades.

Key words: climate suitability, wheat-rice double cropping system, Huaihe Watershed