Abstract: Millet shows a strong tolerance to drought and barren soil during the process of planting. Millet is also an important strategic reserved crop for sustainable agricultural development in China in the future. It is of great practical significance to discuss the regional adaptability of millet in the context of climate change. Based on the climate suitability model, Anusplin software was used to interpolate the climate resources and climate suitability of 314 meteorological stations in millet growing area in Northern China Region by 1km×1km. The spatial distribution and temporal variation characteristics of climate resources and climate suitability in millet growing season were analyzed in 1960-1989 and 1990-2019. The results showed that: (1) the climate resources in millet growing season in Northern China Region showed that sunshine duration increased from east to west and from south to north; Cumulative precipitation increased from north to south and from west to east. The spatial distribution of mean temperature was higher in the south and lower in the north. With the warming of climate, the mean temperature in millet growing season showed an increasing trend, while sunshine duration and accumulated precipitation showed a decreasing trend. (2) The climate suitability in millet growing season presented a trend of "temperature suitability decreased from east to west and from south to north, precipitation suitability increased from northwest to southeast, and sunshine suitability decreased from northwest to southeast". Due to climate warming, the high value areas of temperature suitability and precipitation suitability increased, while the high value areas of sunshine suitability decreased greatly. (3) According to the calculation results of comprehensive climate suitability, the method of natural break was used to divide it into four grades: most suitable, suitable, sub-suitable and unsuitable. About 21.5% of Northern China Region was the most suitable area for millet planting in 1960-1989 (the first 30 years). As the climate warms, about 10.5% areas changed from the suitable area to the most suitable area in 1990-2019(the last 30 years), mainly in Shandong and Shanxi. In the future, it can be considered to expand the planting area in this region according to the actual situation.

Key words: Climate warming, Millet, Climate suitability, Refined climate zoning