Abstract: Based on the annually extreme minimum temperature data from 101 meteorological stations in Xinjiang during 1961-2010, the fundamental spatialtemporal change characteristics of mean extreme minimum temperature and different guarantee rate(80%, 90%, 95%)extreme minimum temperature were analyzed by using the methods of linear regression, Mann Kendall test and three dimensional and quadratic trend surface simulation and inverse distance square weighting residual error revising based on GIS. The main results are as the follows,(1)mean extreme minimum temperature and different guarantee rate extreme minimum temperature were higher in southern than in northern, and higher in plain and valley than in mountain areas of Xinjiang.(2)On average of whole Xinjiang, the extreme minimum temperature of guarantee rate 80%, 90%, and 95% were lower than mean extreme minimum temperature -2.7℃,-4.2℃ and -5.4℃ respectively, and the difference was gradually increased from southeast to northwest in Xinjiang.(3)In the background of global warming, mean extreme minimum temperature showed a significant increasing trend by the rate of 0.74℃/10y in recent 50 years, and had mutations in 1980. The increasing rate and change range before and after 1980 were larger in north than in south, and in plains than in mountains of Xinjiang. In addition, according to climate index of winter wheat and various fruit trees going through winter safely, the influence of different guarantee rate extreme minimum temperature spatial temporal variation to winter wheat and fruit trees going through winter safely were analyzed. The study results have important reference significance, to science formulates plans for the winter crops planting, choose appropriate cold resistant crop varieties, adopt scientific and effective safety overwintering crops management technology in Xinjiang.

Key words: Xinjiang, Extreme minimum temperature, Guarantee rate, Winter wheat, Fruit trees, Freezing injury