Abstract: Understanding the impact of climate change on plants structure in Inner Mongolian was important basis for making policy effectively.Climate change and its impact on main crops phenophase and planting area in four main grain-producing areas of Inner Mongolia were analyzed based on the climate data in recent 50 years and crops growing season data in recent 27 years.The results showed that temperature of main agricultural areas in Inner Mongolia increased significantly in recent 50 years,accumulated temperature above 10℃ increased by 350～570℃.The temperature of Hetao irrigation area and eastern of Daxinganling increased more than northern of Yinshan and Keerqin area.There was great difference between the eastern and western region on precipitation change.The precipitation during growing season of Keerqin area and eastern of Daxinganling decreased 44mm and 55mm respectively,but increased 10.4mm and 2.4mm in Hetao irrigation area and the northern Yinshan respectively.Spring phenophase of maize was advanced and autumn phenophase was postponed,totally approaching 10~20days,in which the most obvious region was the eastern Daxinganling.As temperature increasing accelerated developing process,the whole growing season of spring wheat and soybean was shortened,but it was not obvious for potato except for its harvesting time delayed a little.Climate warming was closely interrelated with expanding of planting areas of maize and potato,decreasing of planting areas of spring wheat and the northward extension of maize planting boundary.

Key words: Climate Change, Climate Change, Crops phenophase, Inner Mongolia