| In this paper, based on the daily average temperature at eight meteorological stations in the Yulin area during the period of 1970—2012, along with the meteorological data of the first day with temperature ≥10℃ and last day with temperature ≥14℃, calculations of the 80% guarantee rate for the first day with temperature ≥10℃, last day with temperature ≥14℃, days to maturity and ≥10℃ accumulated temperature were carried out to analyze the spatiotemporal variation characteristics of climatic resources of spring maize in the Yulin area over the past 43 years, using the methods of linear trend analysis, accumulative anomaly, t-test and Surfer-based spatial interpolation, etc. The results show that the first day with temperature 10℃ was significantly shifted early with a rate of -1.9 d·10a-1 over the past 43 years, which was mutationally shifted to an earlier date in 1992. While the last day with temperature ≥14℃ had a tendency of being delayed, which was mutationally postponed in 1981. The days to maturity and accumulated temperature ≥10℃ had a tendency of being significantly increased at the rate of 2.1 d·10a-1 and 83.12 ℃·10a-1, respectively, which were mutationally increased in 1986 and 1995. The regional variation amounts of each element differed significantly before and after the mutant changes. The advancement amplitude of the first day with temperature ≥10℃ and the delayed amplitude of the last day with temperature ≥14℃ both possessed the characteristics of a decreased distribution from northwest to southeast, while amplitudes of days to maturity and accumulated temperature ≥10℃ had been ample in the western region and lean in the eastern. The first day with temperature≥10℃ at 80% climate guarantee rate showed an inter-decadal variation with a gradual advancement. Compared with that in the 1970s, the first day with temperature ≥10℃ at an 80% climate guarantee rate had shifted an advancement of 3～9 days from 2001 to 2012, while the suitable sowing time of maize ranged from the 23rd to 26th in April. Compared with the other decades in the past century, in the 1980s, the last day with temperature ≥14℃ at an 80% climate guarantee rate was delayed mostly by 3～14 days. The days to maturity of spring maize with an 80% climate guarantee rate were increased by 6～16 days in the northwest region of the Yulin area, while became increased by 3～4 days in the southeast reagion over the past 43 years. The ≥10℃ accumulated temperature during days to maturity of spring maize with an 80% climate guarantee rate was generally increased by 200℃～483℃ over the past 12 years, which led to the changes of the ripe cycle and growing regions of maize, namely shifts of planting boundary westwards, and thereby expanding the planting area. |