采用河北省平原区粮食生产大县宁晋县1982—2018年冬小麦产量数据和对应气象数据，对其进行Mann-Kendall（M-K）趋势检验和Sen斜率分析，利用HP滤波法将冬小麦产量分离为气候产量和趋势产量，筛选产量变化较大的年份并揭示主要气象影响因子，进而分析冬小麦产量与气候变化的关系。研究结果表明：冬小麦生育期平均气温、最高气温和最低气温均呈显著上升趋势，上升幅度分别为0.05、0.03和0.07 ℃/a，平均风速呈显著下降趋势，下降幅度为-0.01 m·s-1·a-1；冬小麦实际产量多年平均值为5 330 kg/hm2，实际产量和趋势产量均呈显著上升趋势，气候产量无明显变化趋势，但是变化范围为-1 245~1 376kg/hm2（-41%~26%），说明年际间变化较大；分析典型高产年和低产年气候要素对冬小麦产量的影响，发现播种返青期极端低温（1986年12月8日和9日日最低气温达到-21.2 ℃，1993年1月14—25日最低气温平均值达到-14.1 ℃），拔节-抽穗期补灌不及时（1993年）以及种植后期降水量过多（2008年）会导致小麦减产，日照时数的提高和播种-拔节期气温的升高有利于小麦高产；不同年份造成减产的主导气象要素不同表明了气候要素对小麦减产的复杂性，而不同年份造成增产的主导气象要素相似则表明了气候要素对小麦增产的一致性。

Wheat is one of the main grain crops in China,and in 2019,China′s wheat production reached 133.6 million tons,accounting for 20% of total grain production.Climate change,especially the extreme climate,does a significant impact on winter wheat yield.Identifying the main influencing factors could help farmers to choose appropriate methods to alleviate the risk to wheat production.For different regions,the impact of climate change on winter wheat cultivation varies.Hebei Province is one of the main wheat-producing areas in China,and Ningjin County is the largest wheat-producing county in the plain area of Hebei.Therefore,it is important to analyze and identify the main climatic factors affecting wheat yield in the region and propose corresponding countermeasures to guide local agricultural production and guarantee high and stable crop yields. Mann-Kendall (M-K) trend test and Sen′s slope analysis were performed to obtain the trend of winter wheat production data and corresponding meteorological data from 1982 to 2018 in Ningjin County.The HP filter was used to separate winter wheat yield into climatic yield and trend yield,to screen the years with high yield variability,i.e.,three high yield years and three low yield years,and to reveal the main meteorological factors affecting yields,and then to analyze the relationship between winter wheat yield and climate change. The results showed that the average temperature (0.05 ℃·a-1),maximum temperature (0.03 ℃·a-1) and minimum temperature (0.07 ℃·a-1) in wheat season increased significantly,the average wind speed decreased significantly (-0.01 m·s-1·a-1),and the multi-year mean value of total ET0 was 600 mm with a not clear increasing trend.The multi-year average of actual winter wheat yield was 5 330kg·ha-1.Both the actual and trend yields showed a significant increasing trend with Sen′s slopes of 136 kg/(hm2·a-1) and 139 kg/(hm2·a-1),respectively.Though the climatic yield trend did not show a clear change trend,it varied from -1 245 to 1 376 kg·ha-1(-41%~26%),indicating a great variation in different years.The climate variables in big low yield and high yield seasons were analyzed and the main factors to influence wheat yield were summarized.Generally,extremely low temperature during the sowingregreening period (for example December 8 and 9,1986,the daily minimum temperature reached -21.2 ℃,and the average minimum temperature from January 14 to 25,1993 reached -14.1 ℃),un-sufficient irrigation during a jointingheading period (1993) and excessive precipitation in late planting period (2008) would lead to wheat yield reduction.The increases in sunshine hours and temperature are beneficial to wheat production. The trends of climate elements are consistent with the findings of most studies in the north China plain,indicating that climate change in the study area is consistent with the trends of climate change at larger spatial scales.Yields in the study area increased at a faster rate in the 1990′s,indicating a significant increase in the level of winter wheat cultivation during that period.The influence of climate factors on winter wheat yield in low yield years shows that extremely low temperatures during the sowingregreeningperiod,un-sufficient irrigation during the jointingheading period,and excessive precipitation in the late planting period can all lead to wheat yield reduction.The main meteorological factors causing yield reduction varied with growth seasons,indicating the complexity of climate effects on wheat yield production.The influence of climate factors on winter wheat yield in highyielding years shows that the increase in sunshine hours is more beneficial to wheat yield under the condition that the temperature remains consistent with the multi-year average.The main meteorological factors causing yield increase are similar in different years,indicating the consistency of climate factors on wheat yield increase.