Changes in the distribution pattern of Hulunbuir grassland cover and its spatial and temporal trend were analyzed to discover the effects of ecological engineering implementation and provide a scientific basis for reasonable development and utilization of grassland. Based on the Landsat4/5 TM remoting sensing images in the year 2000,2005 and 2010,and the maximum likelihood method was adopted to supervise and classify the results and to investigate the distribution pattern of land cover during different periods. By making transfer matrix between different land types in different period, the mutual transformation results were quantitatively analyzed between different land types in different periods. The results proved that: 1) The reducing area of grassland each year was 3 063.03 hm~2/a, the area was transformed dramatically with the unused land, arable land and wetland; The reducing area of water is 3 960.98 hm~2/a, the area transform dramatically with wetland and unused land;2)Arable land, building lot and unused land were increased at different levels;3)The changes of woodland and wetland were relatively stable. In conclusion, due to climate changes, agricultural development and land construction from year 2000 to 2010, the area of Hulunbuir grassland and water area, which transformed into arable land, construction land and unused land, reduced distinctively. In general, the ecological protection of Hulunbuir grassland and water areas and grassland is in tough situation.