As the core components of Hulunbuir Steppe, Xinbaerhuyouqi, Xinbaerhuzuoqi, Chenbaerhuqi, and Ewenkezuzizhiqi were selected as the key study area. Pixel decomposition model was introduced to retrieve the fraction of vegetation coverage (FVC) utilizing the MODIS NDVI data set, and the time series of vegetation coverage was reconstructed. Then, the temporal-spatial changes of FVC time series for study region over the 15-year period from 2000 to 2014 were analyzed. Especially, the algorithm of checking abnormal-point was also introduced, combining the same period of meteorological data of this area to investigate the interior driving forces between FVC and meteorological factors. The FVC distribution of 2014 showed that the higher level vegetation coverage mainly distributed in the east of study area; on the contrary, the lower level of that mainly distributed in the west of study area. Especially, the lowest vegetation coverage existed in the southwest of the study area. Further study of FVC changes showed that the vegetation coverage of whole study area decreased in the first 10 years, while that increased slowly in the latter 5 years. Additionally, the abnormal points which occurred in green-up and green-end periods had much more significant correlation with temperature; while the abnormal points which occurred from July to August strongly correlated with precipitation.