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 spa-tiotemporal 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 re-sults 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 tempera-ture ≥10℃ had a tendency of being significantly increased at the rate of 2.1 d·10a -1 and 83.12 ℃·10a -1,respec-tively,which were mutationally increased in 1986 and 1995 .The regional variation amounts of each element differed sig-nificantly 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 distribu-tion from northwest to southeast,while amplitudes of days to maturity and accumulated temperature ≥10℃ had been am-ple 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 tem-perature ≥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 re-gions of maize,namely shifts of planting boundary westwards,and thereby expanding the planting area.%基于榆林地区8个气象站1970—2012年日平均气温、≥10℃初日和≥14℃终日气象资料，计算80％保证率下≥10℃初日、≥14℃终日、全生育天数及≥10℃积温，采用线性趋势分析、累积距平、t 检验和基于 Surfer 的空间插值等方法对榆林地区近43 a 春玉米气候资源时空变化特征进行分析。结果表明：近43 a 榆林≥10℃初日以－1．9 d·10a －1倾向率呈显著提前趋势，1992年发生突变性提前，≥14℃终日有推后趋势，1981年发生突变性推迟。春玉米生育期天数和≥10℃积温分别以2．1 d·10a －1和83．12℃·10a －1的倾向率呈显著增加趋势，分别于1986年和1995年发生突变性增加。突变前后各要素变化量区域差异明显，≥10℃初日提前幅度和≥14℃终日推后幅度均呈由西北向东南递减分布特征；生育期天数及≥10℃积温增幅呈现西多东少的特点。80％保证率下≥10℃初日呈逐渐提前的年代际变化特征，2001—2012年80％保证率下≥10℃初日较20世纪70年代提前3～9 d，玉米适宜播种期为4月23日至26日。80％保证率下的≥14℃终日20世纪80年代出现最晚，较其它年代推后3～14 d。近43 a 间80％保证率下春玉米全生育期天数榆林西北部增加6～16 d，东南部增加3～4 d。近12 a 来80％保证率下春玉米生育期≥10℃积温较70年代普遍增加200℃～483℃，使玉米熟制和布局发生变化，种植界限西移，范围扩大。
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