Based on dimidiate pixel model, the normalized difference vegetation index (NDVI) datasets deduced from MODIS product were used to calculate the fractional vegetation cover (FVC) in the eastern agricultural region of Qinghai Province in vegetation growing season(Apr.-Sep.) from 2000 to 2009. The correlation coefficient method and the ordered clustering analysis method were applied to detect the spatiotemporal trend and identify abrupt change points. In addition, DEM was considered to investigate the influence of terrain factors on fractional vegetation cover. The results indicated that: 1) fractional vegetation cover of the study area showed a slightly upward trend from 2000 to 2009 and the change was not significant; The year of 2001 was a significant abrupt change point, suggesting that the fractional vegetation cover changed significantly. 2) According to the analysis of fractional vegetation cover responding to terrain factors, the abrupt change points of fractional vegetation cover can be found at: 2500 m and 4100 m in the elevation zones, 4 degrees and 26 degrees in the slope zones, respectively. The trend and the abrupt change points in each specific elevation zone and slope zone were obtained through the investigation of interannual variation and abrupt change year between fractional vegetation cover and both elevation and slope zones. Furthermore, the contributing factors to spatiotemporal variation of fractional vegetation cover and its responding to terrain factors were further discussed. It can be conclude that changes in precipitation and returning cultivated land into forest measurs were the important influence factors, but the latter had a greater influence.