Abstract: In order to grassland ecological environment better adapted to climate change and the reasonable arrangement of animal husbandry production, according to the nearly 1984-2012, Xilingol League area 3 agriculture (animal husbandry) experimental stations of Ulmus pumila phenological observation data, by using the methods of climate trend analysis and correlation analysis, the Ulmus pumila leaves change color in the fall of the stirring and spring phenology characteristics analysis. The results showed that: the average nearly 30 years to Ulmus pumila spring buds open issue had delayed trend, union-wide average delay rate was 10.1 d/ 10 a, which appeared after the first 10 years of 21st century years time, the highest percentage in the 1990s and 3 years recent times; autumn Ye Quan discoloration period had a tendency to delay, union-wide average delay rate was 3.9 d/ 10 a, which appeared in the 1990s and the 21st century’s first decade later year maximum percentage; union-wide except Xilinhaote and Taipusiqi respectively with the highest temperature and lowest ground temperature had significant effects on Ulmus pumila phenophase, the rest of other temperature effect was not obvious; nearly 30 years overall backwards in Xilingol League area in spring, autumn phenophase, the delayed growth season.