Abstract: Global warming has led to frequent extreme events such as high temperatures, droughts, and heavy rainfall in China, severely affecting sustainable socioeconomic development. Agriculture, being highly climate-sensitive, has been significantly impacted. Henan Province, as a major grain-producing region in China, has been significantly impacted by climate change in terms of its grain production. Utilizing meteorological data from the 1 km resolution dataset of China (1980–2020) and projection results of annual precipitation and annual mean temperature from three CMIP6 climate models for the future period, trend analysis, mutation analysis, and sensitivity analysis were employed to investigate the characteristics of regional climate change and its impacts on grain yield and climatic potential productivity(CPP). The results were indicated: 1) From 1980 to 2020, the annual mean temperature in Henan Province increased significantly at a rate of 0.04 ℃·a⁻¹ (P<0.01). In contrast, annual precipitation showed a non-significant upward trend of 0.50 mm·a⁻¹, demonstrating a warming and humidifying trend in the climate of Henan Province. Spatially, annual mean temperature increases were relatively uniform across regions, while the southern Henan Province had the highest precipitation, and the central Henan Province experienced the fastest decline in sunshine hours. 2) From 1980 to 2020, grain yield per unit area rose significantly over the study period. However, climatic yield exhibited periodic fluctuations, strongly influenced by droughts and floods, indicating that the continuous progress of technology had offset the negative impacts of climatic factors to a certain extent. Its volatility of climatic yield and its correlation with climatic factors presented spatial heterogeneity in different regions, which was influenced by topographical and irrigation conditions. 3) CPP, estimated using the Thornthwaite Memorial model, was found to fluctuate between 10 000 and 14 000 kg·hm⁻², with an average value of 12 368 kg·hm⁻². Its annual increasing trend of 18.99 kg·hm⁻²·a⁻¹ was not statistically significant. Precipitation was identified as the dominant climatic factor influencing CPP. 4) Future projections under all SSP scenarios (SSP1-1.9, SSP2-4.5, SSP5-8.5) indicated non-significant increases in CPP by 2030–2060 in Henan Province. A low radiative forcing scenario (SSP1-1.9) was found to present more favorable climatic conditions for crop growth. 5) The climate resources use efficiency in Henan Province had been shown to be in a steady increasing trend, but remained around 40%, suggesting that current grain production has not yet reached the ceiling of climatic potential. It was recommended that the existing land use pattern be maintained, farm activities be optimized in line with crop characteristics; meanwhile, rational regulation of farmland irrigation be comprehensively advanced, and the capacity for preventing and controlling drought and flood disasters be enhanced.