Long-term field monitoring data and historical crop data are useful to assess the impacts of climate change and to manage cropping systems.The objectives of this study are to understand the cropping system response to a warming-drying trend in the northern agro-pastural ecotone(NAE)of China and to document how farmers can adapt to the warming-drying trend by changing cropping system structure and adjusting planting date.The results indicate that a significant warming-drying trend existed in the NAE from 1980 to 2009,and this trend significantly decreased crop(spring wheat,naked oat,and potato)yields.Furthermore,the yield decreased by 16.2%-28.4%with a 1℃increase in maximum temperature and decreased by 6.6%-11.8%with a 10%decrease in precipitation.Considering food security,water use efficiency,and water ecological adaptability in the semi-arid NAE,cropping system structure adjustment(e.g.,a shift from wheat to potato as the predominant crop)and planting date adaptation(e.g.,a delay in crop planting date)can offset the impact of the warming-drying trend in the NAE.Based on the successful offsetting of the impact of the warming-drying trend in the NAE,we conclude that farmers can reduce the negative effects of climate change and minimize the risk of crop failure by adapting their cropping system structure at the farming level. Long-term field monitoring data and historical crop data are useful to assess the impacts of climate change and to manage cropping systems. The objectives of this study are to understand the cropping system response to a warming-drying trend in the northern agro-pastural ecotone (NAE) of China and to document how farmers can adapt to warming-drying trend by changing cropping system structure and adjusting planting date. The results indicate that a significant warming-drying trend existed in the NAE from 1980 to 2009, and this trend significantly decreased crop (spring wheat, naked oat, and potato) yields.Furthermore, the yield decreased by 16.2% -28.4% with a 1 ° C increase in maximum temperature and decreased by 6.6% -11.8% with a 10% decrease in precipitation. Considering food security, water use efficiency, and water ecological adaptability in the semi-arid NAE, cropping system structure adjustment (eg, a shift from wheat to potato as the predominant crop) and planting date adaptation (eg, a delay in crop planting date) can offset the impact of the warming-drying trend in the NAE, we conclude that farmers can reduce the negative effects of climate change and minimize the risk of crop failure by adapting their cropping system structure at the farming level.