Abstract: In this study, MODIS NDVI and EVI data from 41 field measurements in the eastern headwaters of the Yellow River were used. In combination with the alpine grassland coverage data obtained by an Agricultural Digital Camera (ADC), ordinary digital camera (i.e., Canon 70D) and Unmanned Aerial Vehicles (UAV) images, grassland coverage inversion models were constructed using MODIS vegetation indices. The optimal remote sensing model was used to analyze the grassland coverage dynamics from 2000 to 2015. The results indicated that: 1) the correlation between MODIS NDVI and grassland coverage calculated by UAV images was better than that of MODIS EVI and UAV, and the correlation between MODIS EVI and grassland coverage calculated by ADC and Canon images was higher than that of MODIS NDVI and ADC and the Canon 70D. 2) Compared to ADC, the accuracy of the models established using the Canon 70D was much higher, indicating that ordinary digital cameras may be more reliable for calculating the alpine grassland vegetation coverage. 3) Compared with the grassland coverage calculated with the Canon, images from the ADC and UAV under 30 m and 100 m flight height with the two MODIS vegetation indices respectively, the MODIS NDVI was more sensitive to grassland vegetation coverage retrieved by UAV under 30 m flight height; the optimal model was y=65.4132ln(NDVI)+109.1763 (R²=0.7575, RMSEP=8.4780). 4) Vegetation coverage during the study period in the southeast area of the study area was stable at 71.5%. Increases in vegetation cover occurred primarily in the western and northern regions while decreases in vegetation were mostly found in northern and southern regions of the study area.