Abstract: The temporal and spatial distribution of the boundary temperature of chimonophilous/ thermophilic crops affect the crop phenology and planting area. Based on the surface meteorological observation data of 585 meteorological stations in Chinese from 1961 to 2020, taking the ≥0℃ and ≥10℃ thermal time, the initial and terminate days of thermal time as research indices of agricultural heat resources, based on ANUSPLIN meteorological interpolation software, the spatio-temporal evolution of boundary temperature of chimonophilous/ thermophilic crops in China were analyzed from interannual and interdecadal time scales. The influence of heat resource change on agricultural production pattern in Chinese Mainland was also discussed. The results showed that: affected by latitude and topography, the heat resources changed greatly in China. The thermal time ≥0℃ and ≥10℃ in the eastern region presented a ladder distribution with latitude, while in the western region, it was mainly affected by altitude, which decreased gradually from south to north. The thermal time ≥0℃ and ≥10℃ ranged of 700.0−8960.0℃·d and 46.3−8960.0℃·d respectively, with the average climate trend of 72.8℃·d·10y⁻¹ and 73.7℃·d·10y⁻¹. Within 60 years, the initial ordinal number of 0℃ and 10℃ was advanced by 9.6d and 8.4d respectively, and the terminate ordinal number was postponed by 4.8d and 7.8d, respectively. The advance of the initial day and the delay of the final day increased the number of continuous days with daily average temperature ≥0℃ and ≥10℃ by 14.4d and 16.2d in 60 years, respectively. 2011−2020（P6 period）was the warmest 10 years in the study period, that of the thermal time ≥0℃ and ≥10℃ increased by 6.3% and 8.2% respectively compared with P1 period (1961−1970). In P6 period, the area with thermal time ≥0℃ of 6000−7000℃·d increased by 2.11×10⁵km², the area with thermal time ≥10℃ of 5000−6000℃·d increased by 3.37×10⁵km². Under the background of climate warming, the increase of accumulated temperature has had an important impact on China's agricultural system. The layout of agricultural production and planting system should be adjusted in time to fully adapt to climate change.

Key words: Climate change, Heat resources, Boundary temperature, Thermal time